Metabolic Reactions and Energy Transformations in Biochemistry

1. Chapter 4 Checkpoint Answers

2. Checkpoint 1 •  In the reaction (H2O + CO2 H2CO3), increasing the concentration of H2O would A. decrease the concentration of H2CO3.*B. increase the concentration of H2CO3.C. increase the concentration of CO2.D. have no effect on either CO2 or H2CO3 concentrations.

3. Checkpoint 2 1. Energy transformations result in a(n) ______________ in entropy. *A. increase B. decrease C. no change 2. Oxidizing agents accept electrons from molecules undergoing reduction. (T) 3.  A reducing agent donates electrons to a molecule. (T) 4.  Exergonic reactions proceed with the release of energy. (T) 5.  A molecule that gains a hydrogen is also oxidized. (F) 6.  Chemically reduced FAD has __________ extra hydrogen atom(s) bound to it.  A. one *B. two C. three D. no 7.  Oxidized nicotinamide adenine dinucleotide (NAD) has ______________ two hydrogens. *A. lost B. gained C. shared

4. Chapter 5 Checkpoint Answers

5. Checkpoint 1 • 1. ______________ is the opposite of glycogenesis. A. GlycolysisB. Glyconeogenesis*C.GlycogenolysisD. Gluconeogenesis • 2. Glucose formed from amino acids comes from the process of glycogenolysis.  (F) • 3. The Cori cycle involves formation of glucose made by gluconeogenesis in the liver from lactic acid produced by fermentation in skeletal muscles. (T)

6. Checkpoint 2 • 1. In glycolysis, glucose is converted to glycogen.  (F) • 2. Glycolysis converts glucose into two ______________ molecules. A. glycogen B. lactic acid C. acetyl CoA *D. pyruvic acid • 3. Acetyl CoA and NAD are the end-products of the Krebs Cycle.  (F) • 4. Each turn of the Krebs cycle produces A. 2 FADH2, 1 ATP, and 3 NADH. *B. 1 FADH2, 1 ATP, and 3 NADH.C. 3 FADH2, 2 ATP, and 1 NADH. D. 1 FADH2, 3 ATP, and 2 NADH • 5. The actual yield of ATP from 1 glucose is A. 18-20 ATP. B. 36-38 ATP.*C. 30-32 ATP. D. 26-28 ATP.

7. Checkpoint 3 • 1. Which of the following can undergo metabolic conversion to acetyl CoA and enter the Krebs cycle? A. glucose B. fatty acidsC. protein *D. All of these choices are correct. • 2. The majority of energy within the body is stored as triglycerides. (T) • 3. Acetyl CoA A. can enter the Krebs cycle.B. can reversibly form ketone bodies.C. can directly form pyruvic acid.*D. Both can enter the Krebs cycle and can reversibly form ketone bodies. • 4. How many amino acids are essential for an adult? *A. eight B. nine C. ten D. twelve

8. Chapter 6 Checkpoint Answers

9. Checkpoint 1 • 1. The majority of water within the body is found in the *A. intracellular compartment. B. extracellular compartment.C. blood plasma. D. interstitial fluid. • 2. The extracellular matrix is made up of collagen, elastin, and a gel-like ground substance. (T) • 3. Active transport does not require the expenditure of energy.  (F) • 4. Proteins that extend from the cytoskeleton within the cell, through the plasma membrane, and into the extracellular matrix are A. lysosomal proteins. B. metallo proteins.C. receptor proteins. *D. integrin proteins.

10. Checkpoint 2 • 1. Passive transport of water is known as A. filtration. *B. osmosis.C. facilitated diffusion. D. a water pump. • 2. Dialysis uses the process of A. facilitated diffusion. B. primary active transport.*C. simple diffusion. D. secondary active transport. • 3. The rate of diffusion increases as the concentration gradient increases. (T) • 4. What type of intravenous fluid would be given to reduce edema? *A. hypertonic B. isotonic C. hypotonic • 5. Explain the difference between osmolarity and osmolality. (read full explanation in your testbook)

11. Checkpoint 3 • 1. Protein carrier mediated transport of molecules display A. specificity. B. competition.C. saturation. *D. All of these choices are correct. • 2. Glucose can enter into the cell by facilitated diffusion or countertransport.  (F; fasc. diff or cotransport) • 3. Active transport carriers are also called A. vesicles. B. channels.*C. pumps. D. receptors. • 4. What type of functional complex will prohibit paracellular transport? *A. tight junctions B. adherens junctionsC. desmosomes D. gap junctions • 5. Movement of large molecules into a cell is called A. endocytosis. B. exocytosis.C. bulk transport. *D. Both A and C are correct.

12. Checkpoint 4 • 1. The charge difference across a membrane produces the membrane potential.  (T) • 2. The resting membrane potential is closest to the equilibrium potential for A. sodium ions. B. chloride ions.C. calcium ions. *D. potassium ions. • 3. Hyperkalemia would ____________ the resting membrane potential of the cell. A. increase * B. decrease C. have no effect on • 4. A change in the concentration of any ion inside or outside the cell will change the resting potential. (T)

13. Checkpoint 5 • 1. Which of the following is NOT a general category of cell signaling molecules? A. endocrine signaling *B. enzymatic signalingC. paracrine signaling D. synaptic signaling • 2. Which of the following is NOT true of cyclic AMP? *A. It is found on the outside of a plasma membrane.B. It is a second messenger for polar regulatory molecules.C. It is made from ATP.D. It activates enzymes inside a cell to produce the desired effect. • 3. Where is the receptor for a nonpolar, lipid-soluble regulatory molecule? A. embedded in the outer surface of the plasma membraneB. embedded in the inner surface of the plasma membrane*C. in the cytoplasm or nucleus of the cellD. All of the choices are correct.