<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>ATP Hydrolysis Diagram</title>
  <style>
    * {
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      margin: 0;
      padding: 0;
    }

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      width: 100%;
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      flex-direction: column;
      align-items: center;
      padding: 10px 8px 8px;
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      max-width: 580px;
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      align-items: center;
      gap: 8px;
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    .step-desc {
      min-height: 28px;
      font-size: 13.5px;
      line-height: 1.4;
      font-weight: 600;
      color: #1e293b;
      text-align: center;
      padding: 0 6px;
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      position: relative;
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      aspect-ratio: 540 / 235;
      max-height: 255px;
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    svg {
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      height: 100%;
      display: block;
      overflow: visible;
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    /* Controls */
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      display: flex;
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      gap: 8px;
      flex-wrap: wrap;
      justify-content: center;
      width: 100%;
      padding-top: 2px;
    }

    .step-btn {
      padding: 6px 13px;
      font-size: 12px;
      font-weight: 600;
      border-radius: 18px;
      border: 1px solid #cbd5e1;
      background: #f8fafc;
      color: #334155;
      cursor: pointer;
      display: inline-flex;
      align-items: center;
      gap: 4px;
      transition: background-color 0.2s ease, color 0.2s ease, border-color 0.2s ease, box-shadow 0.2s ease;
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      border-color: #0284c7;
      color: #ffffff;
      box-shadow: 0 2px 6px rgba(2, 132, 199, 0.35);
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    .play-btn {
      width: 32px;
      height: 32px;
      border-radius: 50%;
      border: 1px solid #cbd5e1;
      background: #ffffff;
      color: #1e293b;
      font-size: 13px;
      display: flex;
      align-items: center;
      justify-content: center;
      cursor: pointer;
      transition: background-color 0.2s, border-color 0.2s;
    }

    .play-btn:hover {
      background: #f1f5f9;
      border-color: #94a3b8;
    }

    /* SVG State Transitions (Nested group transforms for precise positioning) */
    .p-gamma-mover {
      transition: transform 0.55s cubic-bezier(0.34, 1.3, 0.64, 1);
    }
    .water-mover {
      transition: transform 0.45s cubic-bezier(0.2, 0.9, 0.3, 1), opacity 0.35s ease;
    }
    .cut-indicator {
      transition: opacity 0.3s ease;
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    .energy-mover {
      transition: transform 0.5s cubic-bezier(0.34, 1.4, 0.64, 1), opacity 0.35s ease;
      transform-origin: 0px 0px;
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    .repulsion-group {
      transition: opacity 0.35s ease;
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    .adp-bracket {
      transition: opacity 0.4s ease;
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    .bond-gamma {
      transition: opacity 0.3s ease, stroke-dasharray 0.3s ease;
    }
    .pi-badge {
      transition: opacity 0.4s ease;
    }

    /* State 1: High Tension ATP */
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    .state-1 .water-mover { transform: translate(0, -22px); opacity: 0; pointer-events: none; }
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    .state-1 .pi-badge { opacity: 0; }
    .state-1 .bond-gamma { opacity: 1; stroke-dasharray: none; }

    /* State 2: H2O Attack */
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    .state-2 .water-mover { transform: translate(0, 0); opacity: 1; }
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    .state-2 .bond-gamma { opacity: 0.5; stroke-dasharray: 4 3; }

    /* State 3: Hydrolysis Complete (ADP + Pi + Energy) */
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    .state-3 .adp-bracket { opacity: 1; }
    .state-3 .pi-badge { opacity: 1; }
    .state-3 .bond-gamma { opacity: 0; }

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      .step-desc {
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        min-height: 32px;
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  </style>
</head>
<body>

  <div class="diagram-container">
    <div class="step-desc" id="stepDesc">Step 1: 3 repelling negative phosphate groups store tension ('Compressed Spring').</div>

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          <text x="260" y="31.5" font-size="12" font-weight="800" fill="#991b1b" text-anchor="middle">Compressed Spring State</text>
          
          
          <path d="M 210 93 Q 219 80 228 93 T 246 93" fill="none" stroke="#dc2626" stroke-width="2.5" stroke-linecap="round" />
          <path d="M 272 93 Q 281 80 290 93 T 308 93" fill="none" stroke="#dc2626" stroke-width="2.5" stroke-linecap="round" />
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          <text x="52.5" y="31" font-size="13" font-weight="700" fill="#ffffff" text-anchor="middle">Adenosine</text>
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        <g transform="translate(182, 114)">
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          <text x="0" y="5" font-size="14" font-weight="800" fill="#ffffff" text-anchor="middle">P</text>
          <circle cx="13" cy="-13" r="7.5" fill="#991b1b" />
          <text x="13" y="-10.5" font-size="11" font-weight="900" fill="#ffffff" text-anchor="middle">−</text>
          <text x="0" y="33" font-size="11" font-weight="700" fill="#475569" text-anchor="middle">α</text>
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        <g transform="translate(254, 114)">
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          <text x="0" y="5" font-size="14" font-weight="800" fill="#ffffff" text-anchor="middle">P</text>
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          <text x="13" y="-10.5" font-size="11" font-weight="900" fill="#ffffff" text-anchor="middle">−</text>
          <text x="0" y="33" font-size="11" font-weight="700" fill="#475569" text-anchor="middle">β</text>
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        <line class="bond-gamma" x1="275" y1="114" x2="315" y2="114" stroke="#94a3b8" stroke-width="4" stroke-linecap="round" />

        
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          <g class="p-gamma-mover">
            <circle cx="0" cy="0" r="21" fill="url(#phosGrad)" stroke="#b45309" stroke-width="1.5" />
            <text x="0" y="5" font-size="14" font-weight="800" fill="#ffffff" text-anchor="middle">P</text>
            <circle cx="13" cy="-13" r="7.5" fill="#991b1b" />
            <text x="13" y="-10.5" font-size="11" font-weight="900" fill="#ffffff" text-anchor="middle">−</text>
            <text x="0" y="33" font-size="11" font-weight="700" fill="#475569" text-anchor="middle">γ</text>

            
            <g class="pi-badge" transform="translate(0, 48)">
              <rect x="-44" y="-12" width="88" height="23" rx="11.5" fill="#fef3c7" stroke="#d97706" stroke-width="1.5" />
              <text x="0" y="3.5" font-size="11.5" font-weight="800" fill="#92400e" text-anchor="middle">Pᵢ (Inorganic)</text>
            </g>
          </g>
        </g>

        
        <g class="cut-indicator" transform="translate(295, 114)">
          <line x1="0" y1="-26" x2="0" y2="26" stroke="#dc2626" stroke-width="2" stroke-dasharray="3 3" />
          <text x="0" y="-30" font-size="17" text-anchor="middle">✂️</text>
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        <g transform="translate(295, 54)">
          <g class="water-mover">
            
            <rect x="-26" y="-32" width="52" height="18" rx="9" fill="#e0f2fe" stroke="#0284c7" stroke-width="1" />
            <text x="0" y="-19.5" font-size="10.5" font-weight="800" fill="#0369a1" text-anchor="middle">+ H₂O</text>

            
            
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            <text x="0" y="1" font-size="10" font-weight="800" fill="#ffffff" text-anchor="middle">O</text>
            
            <circle cx="-10" cy="-9" r="6" fill="#38bdf8" stroke="#0284c7" stroke-width="1" />
            <circle cx="10" cy="-9" r="6" fill="#38bdf8" stroke="#0284c7" stroke-width="1" />
            <text x="-10" y="-7" font-size="7.5" font-weight="800" fill="#0f172a" text-anchor="middle">H</text>
            <text x="10" y="-7" font-size="7.5" font-weight="800" fill="#0f172a" text-anchor="middle">H</text>

            
            <path d="M 0 12 L 0 24 M -4 20 L 0 24 L 4 20" stroke="#0284c7" stroke-width="2" stroke-linecap="round" stroke-linejoin="round" />
          </g>
        </g>

        
        <g class="adp-bracket">
          <path d="M 25 152 L 25 160 L 150 160 L 150 168 L 150 160 L 275 160 L 275 152" fill="none" stroke="#2563eb" stroke-width="2" />
          <text x="150" y="185" font-size="13" font-weight="800" fill="#1d4ed8" text-anchor="middle">ADP (Adenosine Diphosphate)</text>
        </g>

        
        <g transform="translate(295, 114)">
          <g class="energy-mover">
            <polygon points="0,-40 12,-16 38,-22 20,0 40,20 16,18 6,40 -6,20 -28,34 -20,8 -40,-4 -16,-12" fill="url(#energyGrad)" filter="url(#burstGlow)" opacity="0.95" />
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            <text x="0" y="4.5" font-size="11" font-weight="800" fill="#991b1b" text-anchor="middle">ΔG = −30.5 kJ/mol</text>
            <text x="0" y="24" font-size="9.5" font-weight="800" fill="#b91c1c" text-anchor="middle">(Exergonic)</text>
          </g>
        </g>
      </svg>
    </div>

    
    <div class="controls">
      <button class="play-btn" id="playToggle" title="Auto play / Pause" aria-label="Toggle auto play">⏸</button>
      <button class="step-btn active" data-step="1">1. ATP Tension</button>
      <button class="step-btn" data-step="2">2. + H₂O Attack</button>
      <button class="step-btn" data-step="3">3. Energy Release</button>
    </div>
  </div>

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      1: "Step 1: 3 repelling negative phosphate groups store tension ('Compressed Spring').",
      2: "Step 2: Water (H₂O) attacks and hydrolyzes the terminal phosphoanhydride bond.",
      3: "Step 3: Bond cleaves into ADP + Pᵢ, releasing usable free energy (ΔG = -30.5 kJ/mol)."
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    // Initialize
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</body>
</html>

ATP Structure, Hydrolysis, and Cellular Energy Coupling

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <meta name="aspect-ratio" content="4:3">
  <title>ATP Energy Coupling</title>
  <style>
    * { box-sizing: border-box; margin: 0; padding: 0; font-family: system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif; }
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      background: #ffffff;
      color: #1e2945;
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      flex-direction: column;
      align-items: center;
      justify-content: space-between;
      min-height: 100%;
      padding: 12px 8px;
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    /* Step Selector Tabs */
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      display: flex;
      gap: 6px;
      width: 100%;
      max-width: 580px;
      justify-content: center;
      flex-wrap: wrap;
    }
    .tab-btn {
      background: #f1f5f9;
      border: 1px solid #cbd5e1;
      color: #475569;
      padding: 6px 10px;
      border-radius: 20px;
      font-size: 12px;
      font-weight: 600;
      cursor: pointer;
      transition: all 0.2s ease;
    }
    .tab-btn.active {
      background: #22b7ff;
      color: #ffffff;
      border-color: #0284c7;
      box-shadow: 0 2px 6px rgba(34, 183, 255, 0.35);
    }

    /* Main Display Area */
    .stage {
      width: 100%;
      max-width: 580px;
      background: #f8fafc;
      border: 1px solid #e2e8f0;
      border-radius: 14px;
      padding: 16px 12px;
      margin: 10px 0;
      display: flex;
      flex-direction: column;
      gap: 14px;
      position: relative;
      overflow: hidden;
    }

    .step-header {
      display: flex;
      justify-content: space-between;
      align-items: center;
      flex-wrap: wrap;
      gap: 8px;
    }
    .step-title {
      font-size: 14px;
      font-weight: 700;
      color: #0f172a;
    }
    .badge {
      display: inline-flex;
      align-items: center;
      gap: 5px;
      padding: 4px 10px;
      border-radius: 20px;
      font-size: 12px;
      font-weight: 700;
    }
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      background: #fee2e2;
      color: #b91c1c;
      border: 1px solid #fca5a5;
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    .badge-green {
      background: #dcfce7;
      color: #15803d;
      border: 1px solid #86efac;
    }
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      background: #e0f2fe;
      color: #0369a1;
      border: 1px solid #7dd3fc;
    }

    /* Reaction Equation Row */
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      display: flex;
      align-items: center;
      justify-content: center;
      gap: 8px;
      flex-wrap: wrap;
      padding: 10px 4px;
      background: #ffffff;
      border-radius: 10px;
      border: 1px dashed #cbd5e1;
      min-height: 80px;
    }

    .molecule {
      display: inline-flex;
      align-items: center;
      gap: 4px;
      padding: 6px 10px;
      border-radius: 8px;
      font-size: 13px;
      font-weight: 700;
      box-shadow: 0 1px 3px rgba(0,0,0,0.06);
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    .mol-nh3 { background: #ccfbf1; color: #115e59; border: 1px solid #99f6e4; }
    .mol-atp { background: #fef3c7; color: #92400e; border: 1px solid #fde68a; }
    .mol-adp { background: #ffedd5; color: #9a3412; border: 1px solid #fed7aa; }
    .mol-inter { background: #fae8ff; color: #86198f; border: 1px solid #f0abfc; }
    .mol-gln { background: #dcfce7; color: #166534; border: 1px solid #bbf7d0; }
    .mol-pi { background: #fee2e2; color: #991b1b; border: 1px solid #fecaca; border-radius: 50%; width: 28px; height: 28px; justify-content: center; padding: 0; }

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    }

    /* Energy Breakdown Bar */
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      background: #ffffff;
      border-radius: 10px;
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      padding: 10px 12px;
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    }
    .energy-row {
      display: flex;
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    .val-pos { color: #dc2626; }
    .val-neg { color: #16a34a; }
    .val-net { font-size: 15px; font-weight: 800; }

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    /* Controls */
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      display: flex;
      align-items: center;
      justify-content: center;
      gap: 12px;
      width: 100%;
      max-width: 580px;
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    .btn-ctrl {
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      color: #334155;
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      border-radius: 8px;
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      font-weight: 700;
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      background: #f1f5f9;
    }
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      display: flex;
      gap: 6px;
    }
    .dot {
      width: 10px;
      height: 10px;
      border-radius: 50%;
      background: #cbd5e1;
      cursor: pointer;
      transition: background 0.2s ease;
    }
    .dot.active {
      background: #22b7ff;
      transform: scale(1.15);
    }
  </style>
</head>
<body>

  
  <div class="tabs" id="tabs">
    <button class="tab-btn active" data-step="0">1. Uncoupled</button>
    <button class="tab-btn" data-step="1">2. Coupled Step A</button>
    <button class="tab-btn" data-step="2">3. Coupled Step B</button>
    <button class="tab-btn" data-step="3">4. Net Reaction</button>
  </div>

  
  <div class="stage">
    <div class="step-header">
      <span class="step-title" id="stepTitle">Uncoupled Synthesis</span>
      <span class="badge badge-red" id="statusBadge">✕ Cannot Proceed</span>
    </div>

    
    <div class="reaction-flow" id="reactionFlow">
      
    </div>

    
    <div class="energy-bar-wrap">
      <div class="energy-row">
        <span id="energyLabel">Reaction Free Energy (ΔG):</span>
        <span id="energyValue" class="val-pos">+14.2 kJ/mol</span>
      </div>
      <div class="meter-container">
        <div class="meter-fill" id="meterFill" style="width: 75%; background: #ef4444;"></div>
      </div>
    </div>
  </div>

  
  <div class="controls">
    <button class="btn-ctrl" id="prevBtn">← Prev</button>
    <button class="btn-ctrl" id="playBtn">⏸ Pause</button>
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    <div class="dots" id="dotsContainer">
      <div class="dot active" data-step="0"></div>
      <div class="dot" data-step="1"></div>
      <div class="dot" data-step="2"></div>
      <div class="dot" data-step="3"></div>
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          <div class="molecule mol-glu">Glutamic Acid</div>
          <span class="symbol">+</span>
          <div class="molecule mol-nh3">NH₃</div>
          <span class="arrow arrow-blocked">↛</span>
          <div class="molecule mol-gln" style="opacity:0.4;">Glutamine</div>
        `,
        energyLabel: "Synthesis ΔG:",
        energyValue: "+14.2 kJ/mol",
        energyClass: "val-pos",
        meterWidth: "75%",
        meterColor: "#ef4444"
      },
      {
        title: "2. Coupled Step A: Phosphorylation",
        badgeText: "⚡ Intermediate Formed",
        badgeClass: "badge-blue",
        equationHtml: `
          <div class="molecule mol-glu">Glutamic Acid</div>
          <span class="symbol">+</span>
          <div class="molecule mol-atp">ATP</div>
          <span class="arrow">→</span>
          <div class="molecule mol-inter">Glu—Ⓟ</div>
          <span class="symbol">+</span>
          <div class="molecule mol-adp">ADP</div>
        `,
        energyLabel: "ATP Phosphorylation:",
        energyValue: "Phosphate Transferred",
        energyClass: "val-neg",
        meterWidth: "45%",
        meterColor: "#3b82f6"
      },
      {
        title: "3. Coupled Step B: Ammonia Displacement",
        badgeText: "✦ Phosphate Released",
        badgeClass: "badge-blue",
        equationHtml: `
          <div class="molecule mol-inter">Glu—Ⓟ</div>
          <span class="symbol">+</span>
          <div class="molecule mol-nh3">NH₃</div>
          <span class="arrow">→</span>
          <div class="molecule mol-gln">Glutamine</div>
          <span class="symbol">+</span>
          <div class="molecule mol-pi">Pᵢ</div>
        `,
        energyLabel: "Displacement:",
        energyValue: "Product Completed",
        energyClass: "val-neg",
        meterWidth: "30%",
        meterColor: "#3b82f6"
      },
      {
        title: "4. Overall Net Coupled Reaction",
        badgeText: "✓ Spontaneous / Proceeds",
        badgeClass: "badge-green",
        equationHtml: `
          <div class="molecule mol-glu">Glu</div>
          <span class="symbol">+</span>
          <div class="molecule mol-nh3">NH₃</div>
          <span class="symbol">+</span>
          <div class="molecule mol-atp">ATP</div>
          <span class="arrow">→</span>
          <div class="molecule mol-gln">Glutamine</div>
          <span class="symbol">+</span>
          <div class="molecule mol-adp">ADP</div>
          <span class="symbol">+</span>
          <div class="molecule mol-pi">Pᵢ</div>
        `,
        energyLabel: "Net ΔG (+14.2 - 30.5):",
        energyValue: "-16.3 kJ/mol",
        energyClass: "val-neg val-net",
        meterWidth: "85%",
        meterColor: "#22c55e"
      }
    ];

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    let isPlaying = true;

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      energyLabel.textContent = data.energyLabel;
      energyValue.textContent = data.energyValue;
      energyValue.className = data.energyClass;
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      meterFill.style.backgroundColor = data.meterColor;

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      playBtn.textContent = "⏸ Pause";
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      autoPlayTimer = null;
      isPlaying = false;
      playBtn.textContent = "▶ Play";
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      nextStep();
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      stopAutoPlay();
      prevStep();
    });

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      if (isPlaying) stopAutoPlay();
      else startAutoPlay();
    });

    // Initialize
    renderStep(0);
    startAutoPlay();
  </script>
</body>
</html>

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <style>
    * { box-sizing: border-box; margin: 0; padding: 0; }
    html, body {
      width: 100%;
      min-height: 100%;
      background: #ffffff;
      font-family: system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
      color: #0f172a;
      display: flex;
      flex-direction: column;
      justify-content: center;
      align-items: center;
      padding: 10px;
    }

    .grid-container {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 10px;
      width: 100%;
      max-width: 660px;
    }

    @media (max-width: 520px) {
      .grid-container {
        grid-template-columns: 1fr;
        gap: 12px;
      }
    }

    .work-card {
      background: #f8fafc;
      border: 1px solid #cbd5e1;
      border-radius: 10px;
      padding: 10px 6px 8px;
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: space-between;
      gap: 4px;
      position: relative;
    }

    .card-title {
      font-size: 13px;
      font-weight: 700;
      color: #0f172a;
      text-align: center;
      line-height: 1.2;
    }

    .card-badge {
      font-size: 11px;
      font-weight: 600;
      color: #0369a1;
      background: #e0f2fe;
      border: 1px solid #bae6fd;
      padding: 2px 8px;
      border-radius: 999px;
      text-align: center;
      white-space: nowrap;
    }

    .stage {
      width: 100%;
      height: 130px;
      display: flex;
      align-items: center;
      justify-content: center;
    }

    svg {
      width: 100%;
      height: 100%;
      display: block;
    }

    /* ATP / Pi styling */
    .atp-badge {
      fill: #b45309;
      font-size: 8.5px;
      font-weight: 800;
      text-anchor: middle;
      dominant-baseline: central;
    }

    .pi-badge {
      fill: #ffffff;
      font-weight: 800;
      font-size: 8px;
      text-anchor: middle;
      dominant-baseline: central;
    }

    /* Animations - Slow, calm, informative loops with dwell times >= 500ms */
    @keyframes synthAnim {
      0%, 25% { transform: translate(0, 0); }
      40%, 75% { transform: translate(-14px, 0); }
      90%, 100% { transform: translate(0, 0); }
    }

    @keyframes phosphateTransfer {
      0%, 20% { opacity: 0; transform: scale(0.6) translateY(-8px); }
      35%, 75% { opacity: 1; transform: scale(1) translateY(0); }
      88%, 100% { opacity: 0; transform: scale(0.6) translateY(6px); }
    }

    @keyframes pumpTransport {
      0%, 18% { transform: translateY(18px); opacity: 0; }
      28%, 68% { transform: translateY(0px); opacity: 1; }
      80%, 100% { transform: translateY(-22px); opacity: 0; }
    }

    @keyframes gateOpen {
      0%, 22% { transform: scaleY(1); }
      38%, 68% { transform: scaleY(0.78) rotate(4deg); }
      84%, 100% { transform: scaleY(1); }
    }

    @keyframes walkFootA {
      0%, 18% { transform: translate(0, 0); }
      30%, 48% { transform: translate(14px, -8px); }
      60%, 82% { transform: translate(22px, 0); }
      92%, 100% { transform: translate(0, 0); }
    }

    @keyframes walkFootB {
      0%, 48% { transform: translate(0, 0); }
      60%, 78% { transform: translate(14px, -8px); }
      88%, 100% { transform: translate(22px, 0); }
    }

    @keyframes stalkTilt {
      0%, 18% { transform: rotate(0deg); }
      35%, 55% { transform: rotate(4deg); }
      68%, 85% { transform: rotate(-3deg); }
      100% { transform: rotate(0deg); }
    }

    .anim-monomer { animation: synthAnim 5s ease-in-out infinite; }
    .anim-phosphate { animation: phosphateTransfer 5s ease-in-out infinite; transform-origin: 112px 58px; }
    .anim-na { animation: pumpTransport 4.8s ease-in-out infinite; }
    .anim-gate { animation: gateOpen 4.8s ease-in-out infinite; transform-origin: 50% 50%; }
    .anim-foot-a { animation: walkFootA 5s ease-in-out infinite; }
    .anim-foot-b { animation: walkFootB 5s ease-in-out infinite; }
    .anim-stalk { animation: stalkTilt 5s ease-in-out infinite; transform-origin: 90px 48px; }
  </style>
</head>
<body>

  <div class="grid-container">
    
    
    <div class="work-card">
      <div class="card-title">Chemical Work</div>
      <div class="stage">
        <svg viewBox="0 0 180 135">
          <defs>
            <linearGradient id="monoGrad1" x1="0" y1="0" x2="1" y2="1">
              <stop offset="0%" stop-color="#34d399" />
              <stop offset="100%" stop-color="#059669" />
            </linearGradient>
          </defs>

          
          <path d="M 22,96 Q 90,66 158,96 L 158,124 Q 90,114 22,124 Z" fill="#e2e8f0" stroke="#94a3b8" stroke-width="1.5" />
          <text x="90" y="114" font-size="9.5" font-weight="700" fill="#0f172a" text-anchor="middle">Enzyme Active Site</text>

          
          
          <circle cx="68" cy="72" r="13" fill="url(#monoGrad1)" stroke="#047857" stroke-width="1.5" />
          <circle cx="64" cy="68" r="3" fill="#a7f3d0" opacity="0.7"/>

          
          <g class="anim-monomer">
            <circle cx="114" cy="72" r="13" fill="url(#monoGrad1)" stroke="#047857" stroke-width="1.5" />
            <circle cx="110" cy="68" r="3" fill="#a7f3d0" opacity="0.7"/>
          </g>

          
          <g class="anim-phosphate">
            <circle cx="114" cy="48" r="8" fill="#f59e0b" stroke="#d97706" stroke-width="1.5" />
            <text x="114" y="48" class="pi-badge">Ⓟ</text>
          </g>

          
          <rect x="22" y="14" width="44" height="17" rx="8.5" fill="#fef3c7" stroke="#f59e0b" stroke-width="1.2" />
          <text x="44" y="23" font-size="9" font-weight="800" fill="#b45309" text-anchor="middle" dominant-baseline="central">ATP</text>
          
          <path d="M 68,22 Q 88,20 98,36" fill="none" stroke="#f59e0b" stroke-width="1.8" stroke-dasharray="3,2" />
          <polygon points="101,38 95,33 101,31" fill="#f59e0b" />
        </svg>
      </div>
      <div class="card-badge">Polymer Synthesis</div>
    </div>

    
    <div class="work-card">
      <div class="card-title">Transport Work</div>
      <div class="stage">
        <svg viewBox="0 0 180 135">
          <defs>
            <linearGradient id="pumpGrad" x1="0" y1="0" x2="0" y2="1">
              <stop offset="0%" stop-color="#818cf8" />
              <stop offset="100%" stop-color="#4f46e5" />
            </linearGradient>
          </defs>

          
          <rect x="12" y="52" width="52" height="6" rx="2" fill="#cbd5e1" />
          <rect x="116" y="52" width="52" height="6" rx="2" fill="#cbd5e1" />
          <rect x="12" y="72" width="52" height="6" rx="2" fill="#cbd5e1" />
          <rect x="116" y="72" width="52" height="6" rx="2" fill="#cbd5e1" />
          <line x1="22" y1="58" x2="22" y2="72" stroke="#94a3b8" stroke-width="1.5" stroke-dasharray="2,2"/>
          <line x1="44" y1="58" x2="44" y2="72" stroke="#94a3b8" stroke-width="1.5" stroke-dasharray="2,2"/>
          <line x1="128" y1="58" x2="128" y2="72" stroke="#94a3b8" stroke-width="1.5" stroke-dasharray="2,2"/>
          <line x1="150" y1="58" x2="150" y2="72" stroke="#94a3b8" stroke-width="1.5" stroke-dasharray="2,2"/>

          
          <g class="anim-gate">
            <path d="M 64,40 C 72,40 74,62 62,92 C 60,94 74,94 76,82 C 78,70 72,42 64,40 Z" fill="url(#pumpGrad)" stroke="#3730a3" stroke-width="1.5" />
            <path d="M 116,40 C 108,40 106,62 118,92 C 120,94 106,94 104,82 C 102,70 108,42 116,40 Z" fill="url(#pumpGrad)" stroke="#3730a3" stroke-width="1.5" />
          </g>

          
          <circle cx="62" cy="100" r="7.5" fill="#f59e0b" stroke="#d97706" stroke-width="1.5" />
          <text x="62" y="100" class="pi-badge">Ⓟ</text>

          
          <g class="anim-na">
            <circle cx="90" cy="60" r="6.5" fill="#0ea5e9" stroke="#0284c7" stroke-width="1.5" />
            <text x="90" y="60" font-size="7" font-weight="800" fill="#ffffff" text-anchor="middle" dominant-baseline="central">Na⁺</text>

            <circle cx="90" cy="78" r="6.5" fill="#0ea5e9" stroke="#0284c7" stroke-width="1.5" />
            <text x="90" y="78" font-size="7" font-weight="800" fill="#ffffff" text-anchor="middle" dominant-baseline="central">Na⁺</text>
          </g>

          
          <path d="M 90,32 L 90,16" fill="none" stroke="#0284c7" stroke-width="2" />
          <polygon points="90,11 86,18 94,18" fill="#0284c7" />

          
          <text x="144" y="24" font-size="8.5" font-weight="700" fill="#475569">[High Na⁺]</text>
          <text x="144" y="112" font-size="8.5" font-weight="700" fill="#475569">[Low Na⁺]</text>
        </svg>
      </div>
      <div class="card-badge">Na⁺/K⁺ Ion Pumping</div>
    </div>

    
    <div class="work-card">
      <div class="card-title">Mechanical Work</div>
      <div class="stage">
        <svg viewBox="0 0 180 135">
          <defs>
            <linearGradient id="cargoGrad" x1="0" y1="0" x2="1" y2="1">
              <stop offset="0%" stop-color="#f43f5e" />
              <stop offset="100%" stop-color="#be123c" />
            </linearGradient>
            <linearGradient id="trackGrad" x1="0" y1="0" x2="0" y2="1">
              <stop offset="0%" stop-color="#e2e8f0" />
              <stop offset="100%" stop-color="#94a3b8" />
            </linearGradient>
          </defs>

          
          <g>
            <rect x="14" y="108" width="152" height="11" rx="5.5" fill="url(#trackGrad)" stroke="#64748b" stroke-width="1.5" />
            <circle cx="28" cy="113.5" r="3.5" fill="#cbd5e1" />
            <circle cx="48" cy="113.5" r="3.5" fill="#cbd5e1" />
            <circle cx="68" cy="113.5" r="3.5" fill="#cbd5e1" />
            <circle cx="88" cy="113.5" r="3.5" fill="#cbd5e1" />
            <circle cx="108" cy="113.5" r="3.5" fill="#cbd5e1" />
            <circle cx="128" cy="113.5" r="3.5" fill="#cbd5e1" />
            <circle cx="148" cy="113.5" r="3.5" fill="#cbd5e1" />
          </g>

          
          <circle cx="90" cy="24" r="14" fill="url(#cargoGrad)" stroke="#9f1239" stroke-width="1.5" />
          <text x="90" y="24" font-size="7.5" font-weight="700" fill="#ffffff" text-anchor="middle" dominant-baseline="central">Vesicle</text>

          
          <g class="anim-stalk">
            <line x1="90" y1="38" x2="90" y2="76" stroke="#475569" stroke-width="2.5" stroke-linecap="round" />
            
            
            <circle cx="72" cy="68" r="6.5" fill="#fef3c7" stroke="#f59e0b" stroke-width="1.2" />
            <text x="72" y="68" font-size="6.5" font-weight="800" fill="#b45309" text-anchor="middle" dominant-baseline="central">ATP</text>
          </g>

          
          
          <g class="anim-foot-a">
            <path d="M 90,76 Q 78,92 72,107" fill="none" stroke="#475569" stroke-width="2.2" stroke-linecap="round" />
            <ellipse cx="72" cy="107" rx="5.5" ry="3.5" fill="#0284c7" stroke="#0369a1" stroke-width="1.5" />
          </g>

          
          <g class="anim-foot-b">
            <path d="M 90,76 Q 102,92 106,107" fill="none" stroke="#475569" stroke-width="2.2" stroke-linecap="round" />
            <ellipse cx="106" cy="107" rx="5.5" ry="3.5" fill="#0284c7" stroke="#0369a1" stroke-width="1.5" />
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          <path d="M 130,48 L 150,48" fill="none" stroke="#059669" stroke-width="1.8" />
          <polygon points="154,48 148,45 148,51" fill="#059669" />
        </svg>
      </div>
      <div class="card-badge">Motor Protein Walking</div>
    </div>

  </div>

</body>
</html>

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <meta name="aspect-ratio" content="16:9">
  <title>The Anatomy of an ATP Molecule</title>
  <style>
    * { box-sizing: border-box; margin: 0; padding: 0; }
    body {
      width: 100%;
      background: #ffffff;
      font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
      color: #1e2945;
      display: flex;
      flex-direction: column;
      align-items: center;
      padding: 12px;
    }
    .controls {
      display: flex;
      gap: 8px;
      flex-wrap: wrap;
      justify-content: center;
      margin-bottom: 12px;
    }
    .btn {
      appearance: none;
      border: 1px solid #e2e8f0;
      background: #f8fafc;
      color: #475569;
      padding: 6px 14px;
      font-size: 13px;
      font-weight: 600;
      border-radius: 9999px;
      cursor: pointer;
      transition: all 0.2s ease;
    }
    .btn:hover { background: #f1f5f9; color: #1e2945; }
    .btn.active {
      background: #2563eb;
      color: #ffffff;
      border-color: #2563eb;
      box-shadow: 0 2px 6px rgba(37, 99, 235, 0.25);
    }
    .diagram-svg {
      width: 100%;
      max-width: 680px;
      height: auto;
      display: block;
      user-select: none;
    }
    .subunit {
      transition: opacity 0.3s ease;
      cursor: pointer;
    }
    .dimmed { opacity: 0.25; }
    .highlight { opacity: 1; }
    .label-title { font-size: 13px; font-weight: 700; text-anchor: middle; }
    .label-sub { font-size: 11px; font-weight: 500; fill: #64748b; text-anchor: middle; }
    .greek-label { font-size: 13px; font-weight: 700; text-anchor: middle; }
    .atom-text { font-size: 13px; font-weight: bold; dominant-baseline: central; text-anchor: middle; }
    .charge-text { font-size: 12px; font-weight: 800; fill: #dc2626; text-anchor: middle; dominant-baseline: central; }
    .bracket-label { font-size: 13px; font-weight: 700; fill: #1e2945; text-anchor: middle; }
  </style>
</head>
<body>
  <div class="controls" role="group" aria-label="Highlight ATP sub-units">
    <button class="btn active" id="btn-all" onclick="highlightUnit('all')">All Units</button>
    <button class="btn" id="btn-adenine" onclick="highlightUnit('adenine')">Adenine</button>
    <button class="btn" id="btn-ribose" onclick="highlightUnit('ribose')">Ribose</button>
    <button class="btn" id="btn-phosphates" onclick="highlightUnit('phosphates')">3 Phosphates</button>
  </div>

  <svg class="diagram-svg" viewBox="0 0 680 320" aria-label="ATP Molecular Structure">
    
    <line x1="184" y1="145" x2="222" y2="145" stroke="#94a3b8" stroke-width="3.5" stroke-linecap="round"/>
    <line x1="344" y1="145" x2="382" y2="145" stroke="#94a3b8" stroke-width="3.5" stroke-linecap="round"/>

    
    <g id="unit-adenine" class="subunit" onclick="highlightUnit('adenine')">
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      <polygon points="75,95 115,95 135,130 115,165 75,165 55,130" fill="#10b981" fill-opacity="0.18" stroke="#059669" stroke-width="2.5" stroke-linejoin="round"/>
      
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      <line x1="75" y1="95" x2="62" y2="72" stroke="#059669" stroke-width="2.5"/>
      <circle cx="56" cy="62" r="12" fill="#ffffff" stroke="#059669" stroke-width="2"/>
      <text x="56" y="62" class="atom-text" font-size="10" fill="#059669">NH₂</text>
      
      <line x1="80" y1="103" x2="110" y2="103" stroke="#059669" stroke-width="2" stroke-linecap="round"/>
      <line x1="128" y1="132" x2="118" y2="156" stroke="#059669" stroke-width="2" stroke-linecap="round"/>
      
      <text x="103" y="214" class="label-title" fill="#047857">Adenine</text>
      <text x="103" y="232" class="label-sub">Nitrogenous Base</text>
    </g>

    
    <g id="unit-ribose" class="subunit" onclick="highlightUnit('ribose')">
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      <polygon points="282,90 324,120 308,168 256,168 240,120" fill="#3b82f6" fill-opacity="0.18" stroke="#2563eb" stroke-width="2.5" stroke-linejoin="round"/>
      
      <circle cx="282" cy="90" r="11" fill="#ffffff" stroke="#2563eb" stroke-width="2.5"/>
      <text x="282" y="90" class="atom-text" font-size="11" fill="#2563eb">O</text>
      
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      <text x="246" y="200" class="atom-text" font-size="10" fill="#2563eb">OH</text>
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Glycolysis in the Cytoplasm: Phosphorylation of Glucose to Hexose Bisphosphate

Glycolysis: Splitting of Hexose Bisphosphate and Oxidation to Pyruvate

Net Energy Yield and Substrate-Level Phosphorylation in Glycolysis

Anaerobic Respiration: Lactate Fermentation and Alcoholic Fermentation

The Link Reaction: Pyruvate Oxidation and Acetyl Coenzyme A Formation

The Krebs Cycle: Formation of Citrate and Successive Decarboxylations

The Krebs Cycle: Dehydrogenation Reactions and Reduced Coenzymes

science

Glycolysis, Anaerobic Pathways, and the Krebs Cycle

ATP Structure and High-Energy Phosphoanhydride Bonds

ATP Hydrolysis and Energy Release

Phosphorylation and Energetic Coupling in Metabolism

ATP Resynthesis and Biological Functions

ATP and Cellular Energetics

Mitochondrial Cristae Adaptations for Respiratory Electron Transport

The Respiratory Electron Transport Chain: Proton Pumping and Redox Carriers

Oxidative Phosphorylation: Chemiosmosis and ATP Synthase

Respiratory Substrates and Calculating the Respiratory Quotient

Investigating Cellular Respiration Using a Respirometer

Oxidative Phosphorylation and Respiratory Energetics

Chloroplast Ultrastructure and Thylakoid Membrane Specialisation

Photosynthetic Pigments, Absorption Spectra and Action Spectra

Photoionisation of Chlorophyll and Photosystems

Photolysis of Water and the Oxygen-Evolving Complex

Non-Cyclic Photophosphorylation and Electron Flow

Cyclic Photophosphorylation and ATP Production

Chemiosmosis Across the Thylakoid Membrane into the Stroma

The Light-Dependent Stage of Photosynthesis

Glycolysis: Glucose Breakdown in the Cytoplasm

The Link Reaction and Pyruvate Decarboxylation

Citric Acid Cycle: Enzymatic Steps and Carbon Turnover

Oxidative Phosphorylation: Electron Transport and Chemiosmosis

Anaerobic Fermentation: Lactic Acid and Alcoholic Pathways

Comparing Aerobic and Anaerobic Respiration Pathways

Cellular Respiration and Energy Transfer

Cellular Respiration: An Exothermic Continuous Process

Aerobic Respiration: Mechanism and Equations

Anaerobic Respiration in Muscles and Oxygen Debt

Anaerobic Respiration in Yeast and Fermentation

Investigating Respiration Rates and Respirometer Maths

Cellular Respiration and Bioenergetics

Czym jest fermentacja — beztlenowe przemiany związków organicznych

Fermentacja alkoholowa — drożdże i warunki procesu

Równanie reakcji fermentacji alkoholowej — od glukozy do etanolu i CO2

Doświadczenie — obserwacja fermentacji alkoholowej i próba z wodą wapienną

OGS.10.CB.5

Aligned learning resources

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