Ex Phys Chapter 6

(Energy Transfer in the body)

What is ATP and why is it so crucial for energy transfer?

ATP is the primary energy currency of cells, storing and transferring energy to power biological processes

The structure of ATP is of Adenosine (Adenine + Ribose) connected to three phosphates (PO4)

True; this is the correct arrangement

The bonds between the __ phosphates are high-energy because they release energy during hydrolysis

2nd and 3rd

What new compound forms when ATP joins with water? And what enzyme catalyzes this reaction?

ADP; ATPase

Which of the following is NOT a function of ATP? (#1)

Oxygen transport

Which of the following is NOT a function of ATP? (#2)

Storage of hereditary information

Why does ATP in cells have to be continually resynthesized?

They contain a small amount of ATP which is continually broken down to release energy

The body normally stores __ grams of ATP which is enough for _ seconds of exercise

80-100 / 2-3

What is the relation between Catabolism and ATP?

Catabolic reactions break down macromolecules to release energy used for synthesizing ATP

What is the relation between Anabolism and ATP?

Anabolism uses energy from ATP to build macromolecules from building blocks

Catabolism is _ and Anabolism is _

Exergonic / Endergonic

Aerobic glycolysis occurs in the __, while Anaerobic glycolysis occurs in the _

Mitochondrion / Cytosol

What is the main difference between Anaerobic and Aerobic glycolysis regarding their substrates and oxygen use?

Anaerobic uses glucose but without oxygen, while Aerobic specifically uses carbs and fats with oxygen

What is Phosphocreatine or Creatine Phosphate (PCr) and it’s function?

PCr is a high-energy molecule that donates a phosphate to ADP to resynthesize ATP

Cells store about 4-6 times more PCr than ATP and it reaches its max energy yield in _ seconds. What is the enzyme catalyzing the reaction using PCr to make ATP?

10 / Creatine phosphokinase

The FINAL electron acceptor in the ETC is __. And the final product is _

Oxygen / Water

Oxidative Phosphorylation synthesizes ATP by transferring electrons from ____?

NADH and FADH₂ to Oxygen

What percent of ATP synthesis takes place in the respiratory chain (powered by Oxidative Phosphorylation / OP)?

90%

Which of the following is NOT one of the three requirements for continual ATP resynthesis during OP?

Availability of phosphocreatine (PCr) in the muscle

What happens during the 1st stage of energy metabolism?

Digestion of large macromolecules which are broken down into smaller subunits

What happens during the 2nd stage of energy metabolism?

Amino acids, glucose, and fatty acids are broken down into acetyl-CoA

What happens during the 3rd stage of energy metabolism?

Acetyl-CoA is oxidized to CO₂ and H₂O, producing substantial amounts of ATP

Which of the following is NOT one of the six fuel sources supplying substrate for ATP formation? (#1)

Phosphocreatine (PCr) stored within muscle cells

Which of the following is NOT one of the six fuel sources supplying substrate for ATP formation? (#2)

Oxygen directly providing the energy required to synthesize ATP

Anaerobic glycolysis is rapid, releases about 5% of the energy of the original glucose molecule. It forms what molecule?

Lactate

Aerobic glycolysis is slow, releases about 95% of the energy of the original glucose molecule. It forms what molecule?

Pyruvate

Carbs supply NRG for cellular work in the form of __. Complete oxidation of a glucose molecule releases _ ATP

Glucose or Glycogen / 34-36

Light to moderate exercise uses what fraction of carbs?

1/3

What enzyme assists with the conversion of glucose —> glucose 6-phosphate?

hexokinase

What is the enzyme phosphorylase involved in?

Breaking down glucose to release glucose 1-phosphate

What enzyme is involved in the conversion of glucose 6-phosphate —> fructose 6-phosphate?

glucose-phosphate isomerase

What enzyme is involved in the conversion of fructose 6-phosphate —> fructose 1, 6-diphosphate?

phosphofructokinase

Which statement best describes rapid glycolysis?

Rapid breakdown of glucose to produce ATP without oxygen

How much ATP is produced net from one glucose molecule during glycolysis?

2

How much ATP is produced gross during glycolysis before accounting for ATP invested earlier in the pathway?

4

Which group contains enzymes involved in glycolysis?

Hexokinase, phosphofructokinase, and pyruvate kinase

Which of the following is NOT considered one of the key enzymes involved in regulating glycolysis?

Creatine kinase

What role does fructose 1,6 bisphosphate (AKA diphosphate) play in glycolysis?

Helps promote glycolytic activity + activate pyruvate kinase

What effect does oxygen availability in abundance have on the reliance on anaerobic glycolysis?

Decreases reliance on anaerobic glycolysis since aerobic metabolism can contribute more to making ATP

What is the primary (70%) use for lactate post-exercise?

Energy production via Citric Acid Cycle

How can lactate contribute to the re-formation of glycogen after exercise?

Lactate can be converted into glucose through the Cori cycle, which can then contribute to glycogen formation

What is the smallest (10%) use for Lactate post-exercise?

Restoring oxygen to the blood cells, myoglobin and lungs

The remaining energy (95%) within glucose is released when pyruvate converts to __

Acetyl-CoA and enters the Citric Acid Cycle

Which of the following is NOT a source of lipid-derived energy during exercise?

Phosphocreatine stored within skeletal muscle

Where do circulating free fatty acids used for energy during exercise primarily come from?

Breakdown of triacylglycerols stored in adipose tissue

Lipids supply about __ % of the energy needed for biologic work

30 to 80

Complete oxidation of a triacylglycerol molecule yields about 460 ATP molecules, well over 12-13 times that of a carbohydrate!

True

Hormone-sensitive lipase stimulates the breakdown of __ into its glycerol + fatty acid components

triacylglycerol (TAG)

The blood transports free fatty acids (FFAs) released from adipocytes and bound to plasma albumin

True

Energy is NOT released when TAG stored within muscle fibers degrades to glycerol and fatty acids

False

In proteins, after deamination, the remaining carbon skeleton enters metabolic pathways to produce ATP aerobically.

True

When deaminated, these yield intermediates for glucose synthesis

Glucogenic amino acids

When deaminated, these yield the intermediates acetyl-CoA or acetoacetate for TAG formation

Ketogenic amino acids