Comprehensive Final: Carbs

Question 1

How do plants synthesize carbohydrates?

Answer 1

Through photosynthesis, combining water and carbon dioxide with solar energy to produce glucose

Question 2

Can humans synthesize carbohydrates?

Answer 2

Yes, but only starting from energy-endowed molecules, not from scratch

Question 3

What is the goal of carbohydrate digestion?

Answer 3

To liberate monosaccharides, primarily glucose, for absorption

Question 4

Where does carbohydrate digestion begin?

Answer 4

In the mouth, with salivary amylase breaking α1-4 links in amylose

Question 5

List Simple carbohydrates

Answer 5

Monosaccharides (Galactose, glucose, fructose) and disaccharides (Maltose, sucrose, lactose).

Question 6

List Complex carbohydrates

Answer 6

Polysaccharides like starch (amylose, amylopectin), glycogen, and fiber (cellulose)

Question 7

What is amylopectin?

Answer 7

A plant-based polysaccharide with branch points every 20-24 glucose units, used for energy storage.

Question 8

What is glycogen?

Answer 8

An animal-based polysaccharide with branch points every 8-12 glucose units, stored in liver and skeletal muscle

Question 9

difference between amylopectin and glycogen

Answer 9

Glycogen has more frequent branch points, allowing faster energy release during metabolism.

Question 10

Which hormone primarily regulates blood glucose levels?

Answer 10

Insulin, which lowers blood glucose by promoting uptake and storage in tissues.

Question 11

Which enzymes in the small intestine break down starch?

Answer 11

Pancreatic amylase and dextrinase

Question 12

What role do disaccharidases play in digestion?

Answer 12

They break disaccharides into monosaccharides, such as:

Sucrase: Sucrose → Glucose + Fructose
Lactase: Lactose → Glucose + Galactose
Maltase: Maltose → Glucose + Glucose.

Question 13

How does insulin affect skeletal muscle and adipose tissue?

Answer 13

It promotes glucose uptake by mobilizing GLUT4 receptors to the cell membrane

Question 14

What happens to excess glucose in the liver?

Answer 14

It is taken up via glucokinase and stored as glycogen.

Question 15

How does exercise intensity affect insulin release?

Answer 15

Insulin release decreases above 50% VO₂max due to catecholamines and growth hormone.

Question 16

How does epinephrine affect blood glucose during exercise?

Answer 16

It increases glycogen breakdown in the liver and glucose release into the blood.

Question 17

What is the role of triglycerides in muscle energy?

Answer 17

They serve as a consistent energy source, particularly at lower intensities.

Question 18

How much carbohydrate should an athlete consume daily?

Answer 18

General fitness: 45-55% of total energy.
Moderate training: 55-65% or 5-8g/kg body weight.
High-intensity training: 8-10g/kg body weight.

Question 19

How much carbohydrate should be consumed 30-60 minutes before exercise?

Answer 19

50-70g.

Question 20

What is the benefit of consuming ≤50g carbohydrate immediately before exercise?

Answer 20

It can enhance performance, similar to carbohydrates consumed during exercise.

Question 21

What is the optimal post-exercise carbohydrate intake?

Answer 21

1.5g/kg body weight within the first 30 minutes, and every 2 hours for 4-6 hours afterward.

Question 22

What is insulin’s effect on the liver?

Answer 22

It promotes glycogen synthesis and inhibits glucose production by enhancing glucokinase activity.

Question 23

What are insulin’s anabolic effects?

Answer 23

It supports the storage of glucose as glycogen, fat synthesis, and protein metabolism.

Question 24

What are the actions of glucagon?

Answer 24

Stimulates glycogen breakdown in the liver.
Promotes gluconeogenesis.
Mobilizes fat stores for energy.

Question 25

What are the actions of insulin?

Answer 25

Increases glucose uptake in muscle and fat cells.
Promotes glycogen synthesis.
Reduces fat breakdown.

Question 26

What are the actions of epinephrine?

Answer 26

Stimulates glycogen breakdown in liver and muscle.
Mobilizes fat stores for energy.

Question 27

What are the actions of cortisol?

Answer 27

Increases protein breakdown for gluconeogenesis.
Mobilizes fat stores.
Enhances liver glucose release.

Question 28

What is intermediate hyperglycemia?

Answer 28

Blood glucose levels between 110-140 mg/dL.

Question 29

What is hyperglycemia?

Answer 29

Elevated blood glucose levels above 140 mg/dL, typically after meals or in conditions like diabetes.

Question 30

What is hypoglycemia?

Answer 30

Low blood glucose levels below 70-75 mg/dL, often causing symptoms like dizziness, fatigue, and confusion.