Midterm 1

Question 1

How do plants create carbohydrates?

Answer 1

water (H2O) & carbon dioxide (CO2) via photosynthesis.

Question 2

What is the primary carbohydrate source in animal products?

Answer 2

Milk (dairy) is the primary carbohydrate source in animal products, as glycogen is depleted during animal slaughter.

Question 3

What is glycogen, and where is it primarily stored in the body?

Answer 3

Glycogen is a stored form of glucose & found in the liver (6-8%) & skeletal muscle (1-2%).

Question 4

How does carbohydrate digestion begin in the body?

Answer 4

In the mouth, salivary amylase starts breaking down starch into smaller sugars.

Question 5

What is the role of insulin in glucose metabolism?

Answer 5

Insulin helps move glucose into muscles and fat, where it is stored as glycogen and used for energy, which helps lower blood sugar (glucose) levels.

Question 6

How does the body respond to elevated blood glucose levels?

Answer 6

The pancreas releases insulin, which promotes glucose uptake in muscle and fat cells, lowering blood glucose levels.

Question 7

What happens to glucose during endurance exercise?

Answer 7

During endurance exercise, eating something with glucose can help you keep going for a longer time before feeling tired.

Question 8

What is the impact of a high-carbohydrate diet on muscle glycogen stores before exercise?

Answer 8

A high-carbohydrate diet increases muscle glycogen stores, enhancing endurance performance and delaying fatigue.

Question 9

What is the recommended carbohydrate intake during endurance exercise?

Answer 9

Endurance athletes should consume 30-60 grams of carbohydrates per hour to maintain blood glucose levels.

Question 10

What are the HORMONAL actions of insulin related to carbohydrates?

Answer 10

Insulin increases glucose uptake in muscle and fat cells, enhances glycogen synthesis, and decreases fat breakdown.

Question 11

What is the role of glucagon in carbohydrate metabolism?

Answer 11

Glucagon increases glycogen breakdown in the liver, releases glucose into the bloodstream, and enhances glucose production in the liver.

Question 12

What is the difference between amylopectin and glycogen?

Answer 12

Both made of glucose, but glycogen has branch points every 8-12 glucose units, while amylopectin branches every 20-24 glucose units.

Question 13

How does exercise intensity affect insulin levels?

Answer 13

High-intensity exercise can inhibit insulin release due to increased levels of epinephrine and other stress hormones.

Question 14

How does muscle glycogen affect exercise performance?

Answer 14

High muscle glycogen levels improve endurance and performance, while depletion is associated with fatigue.

Question 15

What are the carbohydrate intake recommendations for athletes in training?

Answer 15

5-8 g/kg body weight of carbohydrates moderate training and 8-10 g/kg during intense training.

Question 16

What is the recommended carbohydrate intake after exercise?

Answer 16

1.5 grams of carbohydrates per kg of body weight during the first 30 minutes after exercise and then every 2 hours for 4-6 hours.

Question 17

What factors increase the activity of phosphorylase in muscles?

Answer 17

Epinephrine, glucagon, phosphate (Pi), calcium (Ca2+), and AMP enhance glycogen breakdown.

Question 18

What does phosphorylase activity do?

Answer 18

enhance glycogen breakdown.

Question 19

How does glucose tolerance differ in glucose-tolerant vs. glucose-intolerant individuals?

Answer 19

In glucose-intolerant people, blood glucose levels remain elevated longer after ingestion than glucose-tolerant individuals.

Question 20

What is the impact of cortisol on carbohydrate metabolism?

Answer 20

Increases muscle protein breakdown for glucose production, enhancing liver glycogen breakdown and promoting fat mobilization.

Question 21

Why is carbohydrate ingestion before exercise important?

Answer 21

Consuming carbohydrates before exercise maximizes glycogen stores, enhances performance, and delays the onset of fatigue.

Question 22

What happens to carbohydrate digestion in the stomach?

Answer 22

Carbohydrate digestion is halted in the stomach due to the low pH, which inhibits salivary amylase activity.

Question 23

What enzymes are involved in carbohydrate digestion in the small intestine?

Answer 23

Pancreatic amylase and dextrinase keep breaking down starch into maltose and brush border enzymes (sucrase, lactase, maltase) further digest disaccharides.

Question 24

How are glucose and galactose absorbed in the small intestine?

Answer 24

Glucose and galactose are actively absorbed using sodium (Na+) and ATP thus needing energy for transport into the cells.

Question 25

How is fructose absorbed differently from glucose and galactose?

Answer 25

relies on diffusion, no energy required.

Question 26

What happens to absorbed monosaccharides once they enter the bloodstream?

Answer 26

They drain into the portal vein and are transported to the liver for metabolism.

Question 27

What role does the liver play in carbohydrate metabolism?

Answer 27

It removes nearly all fructose and galactose, converting them into glucose, and regulates blood glucose levels by storing or releasing glucose.

Question 28

What effect does insulin have on glucose metabolism?

Answer 28

Insulin promotes the uptake of glucose into muscle and fat cells, mobilizes GluT4 receptors to the cell membrane, and stimulates glycogen storage.

Question 29

What is the normal range of blood glucose levels after carbohydrate absorption?

Answer 29

Resting blood glucose levels range from 70-110 mg/dl and can rise above 140 mg/dl after carbohydrate absorption, triggering insulin release.

Question 30

What is the effect of glucagon during exercise?

Answer 30

Glucagon release from pancreatic α-cells increases blood glucose levels by promoting glycogen breakdown in the liver, supporting energy needs during exercise.

Question 31

How does cortisol influence carbohydrate metabolism during prolonged exercise?

Answer 31

Cortisol levels increase with prolonged exercise, enhancing muscle protein breakdown into amino acids that the liver can convert into glucose for energy.