Body Growth and Energy

Question 1

What is metabolism?

Answer 1

Metabolism encompasses all chemical reactions in the body that are essential for energy transfer and maintaining life.

Question 2

What is a calorie?

Answer 2

A calorie is the unit of energy needed to raise the temperature of 1 gram of water by 1 degree Celsius.

Question 3

How are carbohydrates processed in the body?

Answer 3

Carbohydrates are converted into glucose, which serves as the primary fuel for the body.

Question 4

What happens to excess glucose in the body?

Answer 4

Excess glucose is stored as glycogen in the liver and muscles.

Question 5

Which hormones regulate blood glucose levels?

Answer 5

Insulin and glucagon are the two key hormones that regulate blood glucose levels.

Question 6

What occurs when glycogen stores are depleted?

Answer 6

When glycogen stores are depleted, the body begins to use fats as an energy source.

Question 7

What is glycolysis?

Answer 7

Glycolysis is the process of breaking down glucose into two pyruvate molecules in the cytoplasm.

Question 8

What are the two pathways pyruvate can take after glycolysis?

Answer 8

Pyruvate can undergo aerobic metabolism to become acetyl CoA or anaerobic metabolism to be converted into lactate.

Question 9

What is gluconeogenesis?

Answer 9

Gluconeogenesis is the process of creating new glucose from lactate in the liver, particularly during anaerobic conditions.

Question 10

What is glycogenolysis?

Answer 10

Glycogenolysis is the breakdown of glycogen into glucose, regulated by glucagon.

Question 11

How does lipolysis function?

Answer 11

Lipolysis is the breakdown of stored triglycerides into glycerol and three fatty acids, with glycerol entering the glycolysis pathway.

Question 12

What happens during fatty acid oxidation?

Answer 12

Fatty acids undergo beta oxidation in the mitochondria to form acetyl CoA, which then enters the Krebs cycle.

Question 13

What is ATP and why is it important?

Answer 13

ATP (adenosine triphosphate) is the primary energy carrier in cells. It links energy intake from food with the work done by the body.

Question 14

What role does the sodium-potassium pump play in cellular function?

Answer 14

The sodium-potassium pump uses ATP hydrolysis to move sodium out of the cell and potassium into the cell against their concentration gradients.

Question 15

Describe the mechanism of muscle contraction.

Answer 15

Muscle contraction involves the sliding of actin and myosin filaments, forming crossbridges. ATP is required for the detachment of these filaments, and the process is calcium-dependent.

Question 16

How do cells grow and repair?

Answer 16

Cells grow and repair through processes such as cell enlargement or proliferation (dividing of cells).

Question 17

What is the primary fuel source for red blood cells?

Answer 17

Glucose is the only fuel for red blood cells, necessitating a constant supply of glucose in the body.

Question 18

What happens during anaerobic metabolism when oxygen is not present?

Answer 18

In anaerobic metabolism, pyruvate is converted into lactate, which is then transported to the liver for gluconeogenesis.

Question 19

What is the process of glycogenesis?

Answer 19

Glycogenesis is the formation of glycogen from glucose, which is regulated by the hormone insulin.

Question 20

What are ketone bodies, and when are they used?

Answer 20

Ketone bodies are produced during ketogenesis and can be used as an alternative energy source when glucose availability is low.

Question 21

How is energy released from food?

Answer 21

Energy is released from food by breaking the chemical bonds in food molecules, which is then converted into ATP.

Question 22

Why can’t ATP be stored for long periods?

Answer 22

ATP cannot be stored for long because it is continuously used for energy, and the body relies on constant production from metabolic processes.

Question 23

What is the significance of oxidative phosphorylation?

Answer 23

Oxidative phosphorylation is a key process in cellular respiration that produces large amounts of ATP, along with CO2 and H2O as waste products.

Question 24

What role does the phosphate group play in the sodium-potassium pump?

Answer 24

Hydrolysis of ATP transfers a phosphate group to the Na+/K+ pump, causing a conformational change that allows sodium to be released outside the cell.

Question 25

What happens to acetyl CoA after its formation?

Answer 25

Acetyl CoA enters the Krebs cycle, where it contributes to energy production, and can also be converted into fats during lipogenesis.

Question 26

How does the body utilize glycerol from lipolysis?

Answer 26

Glycerol from lipolysis can enter the glycolysis pathway, where it is used for energy production.

Question 27

In what situation is protein used as a main energy source?

Answer 27

Protein is primarily used as an energy source during extreme starvation when carbohydrate and fat stores are depleted.

Question 28

What is the end product of anaerobic glycolysis?

Answer 28

The end product of anaerobic glycolysis is lactate, which can be converted back to glucose in the liver.

Question 29

What triggers glycogenolysis in the body?

Answer 29

Glycogenolysis is triggered by glucagon, which signals the body to break down glycogen into glucose when blood sugar levels are low.

Question 30

What happens during beta oxidation of fatty acids?

Answer 30

During beta oxidation, fatty acids are broken down in the mitochondria to produce acetyl CoA, which can then enter the Krebs cycle for energy production.

Question 31

How does calcium influence muscle contraction?

Answer 31

Calcium is essential for muscle contraction as it binds to proteins that initiate the sliding of actin and myosin filaments, facilitating crossbridge formation.

Question 32

What is the relationship between ATP and ADP?

Answer 32

ATP is broken down to ADP (adenosine diphosphate) and inorganic phosphate (Pi) during energy release, which can be rephosphorylated to regenerate ATP.