. What is metabolism?

Sum of all chemical reactions in the body.

2. What is anabolism?

Building complex molecules using dehydration synthesis; requires energy (endergonic).

3. What is catabolism?

Breaking down molecules using hydrolysis; releases energy (exergonic).

4. What do enzymes do?

Lower activation energy and speed up reactions without being consumed.

5. What determines enzyme specificity?

The active site shape.

6. What is an enzyme–substrate complex?

Temporary binding that strains bonds and makes reactions more likely.

7. What factors increase reaction rate?

Small particle size, high temperature, high concentration, catalysts.

8. What can denature enzymes?

Extreme temperature, pH, harsh chemicals (e.g., cyanide).

9. What are cofactors?

Metal ions (Fe, Cu, Zn) that activate enzymes.

10. What are coenzymes?

Vitamins (mostly B vitamins).

11. What is ATP made of?

Adenine + ribose + 3 phosphates.

12. What happens when ATP loses a phosphate?

Energy is released; ATP → ADP + Pi.

13. What is phosphorylation?

Adding a phosphate to another molecule.

14. What is substrate‑level phosphorylation?

Direct ATP formation by transferring a phosphate.

15. What is oxidation?

Loss of electrons; releases energy.

16. What is reduction?

Gain of electrons.

17. What is the role of NAD and FAD?

Carry hydrogen/electrons to the ETC.

18. What is oxidative phosphorylation?

ATP production using redox reactions in the ETC.

19. Where does glycolysis occur?

Cytoplasm.

20. Does glycolysis require oxygen?

No.

21. What are the products of glycolysis?

2 ATP (net), 2 NADH, 2 pyruvate.

22. What happens in lactic acid fermentation?

Pyruvate → lactic acid when no oxygen is present.

23. What causes muscle soreness?

Lactic acid accumulation.

24. What happens in alcoholic fermentation?

Pyruvate → ethanol (yeast/bacteria).

25. Where does the Krebs cycle occur?

Mitochondrial matrix.

26. Krebs cycle yield per glucose?

6 NADH, 2 FADH₂, 2 ATP.

27. Where is the ETC located?

Inner mitochondrial membrane.

28. What is the final electron acceptor in the ETC?

Oxygen → forms water.

29. ATP yield per NADH?

3 ATP.

30. ATP yield per FADH₂?

2 ATP.

31. Total ATP from cellular respiration?

36 usable ATP (up to 38 max).

32. What happens to excess monosaccharides?

Stored as glycogen or converted to fat/amino acids.

33. What yields more ATP: fats or carbs?

Fats — an 18‑C fatty acid yields 146 ATP.

34. What is a gene?

DNA segment coding for one protein.

35. What is the genome?

All DNA in a cell.

36. DNA base pairing rules?

A–T (2 H‑bonds), G–C (3 H‑bonds).

37. What is DNA replication?

Semi‑conservative copying during interphase.

38. What is transcription?

DNA → mRNA in the nucleus.

39. What is translation?

mRNA → protein at the ribosome.

40. Start codon?

AUG.

41. Stop codons?

UAA, UAG, UGA.

42. What does tRNA do?

Brings amino acids; has anticodon.

43. What are mutations?

Substitution, inversion, frameshift (addition/deletion).