week three - nutrition and metabolism

Question 1

What is metabolism?

Answer 1

all chemical reaction in the body that maintain life, including those that build up and break down molecules

Question 2

What is catabolism?

Answer 2

metabolic pathways that break down molecules into smaller units

Question 3

What is anabolism?

Answer 3

metabolic pathways that build complex molecules from simpler ones, requiring energy input

Question 4

What hormones lead to hunger and satiation?

Answer 4

Hunger: Ghrelin

Satiation: Leptin, insulin, peptide YY, and Cholecystokinin(cck)

Question 5

What is the role of the arcuate nucleus?

Answer 5

Located in the hypothalamus. it regulates appetite

Question 6

What role does leptin play in appetite?

Answer 6

It decreases appetite

Question 7

What role does Ghrelin play in appetite?

Answer 7

It increases appetite

Question 8

After glucose is absorbed, what else can it be used for?

Answer 8

• ATP production
• stored as glycogen
• converted to fat/lipids

Question 9

What are the stages of cellular respiration?

Answer 9

1. glycolysis
2. pyruvate oxidation
3. citric acid cycle
4. electron transport chain

Question 10

What is gluconeogenesis?

Answer 10

Creation of glucose from non-carbohydrates in the liver and kidneys

Question 11

What is glycogenesis?

Answer 11

Formation of glycogen from glucose in the liver and muscle

Question 12

What is glycogenolysis?

Answer 12

breakdown of glycogen to glucose

Question 13

Why would glycogen form?

Answer 13

it is formed from extra glucose within the body that isn’t used in ATP production and is stored in the liver until used.

Question 14

Why is it important to keep nitrogen in balance?

Answer 14

it helps with protein synthesis. Imbalance of nitrogen can lead to muscle loss or waste build up

Question 15

After an amino acid is absorbed, what can it be used for?

Answer 15

• make proteins
• converted to other amino acids
• converted to fatty acids from acetyl-CoA
• can be used to make glucose

Question 16

After fat is absorbed, what can it be used for?

Answer 16

• stored as triglycerides
• used for ATP
• used in cell membranes or hormones

Question 17

What are the functions of fat?

Answer 17

• energy storage
• insulation and protection
• hormone production
• cell membrane structure

Question 18

How can fats be broken down for energy?

Answer 18

through beta-oxidation: fatty acids are broken down into two carbon fragments

Question 19

Which release more energy: fats or glucose?

Answer 19

Fats

Question 20

What is lipogenesis?

Answer 20

Synthesizing fats from other types of molecules such as carbs or amino acids. It occurs when energy intake exceeds the needs.

Question 21

What type of molecules can be converted to fat?

Answer 21

Glucose or amino acids

Question 22

What molecule must be present in order for fats to be broken down?

Answer 22

Lipase

Question 23

How are lipids transferred? why are they transferred in such a special way?

Answer 23

They become lipoproteins, where the fat cells are wrapped in proteins so they can travel in the blood stream. Lipids are hydrophobic, so they need to be transferred in this special way.

Question 24

What are proteins used for?

Answer 24

• providing structure
• catalyzing reactions
• transporting molecules
• acting as hormones and antibodies

Question 25

What is the general process that has to take place for an amino acid to be catabolized?

Answer 25

1. deamination - removes NH2 from amino acid 2. then it is converted into pyruvate with the remaining acid. 3. the ammonia produced from this is excreted from the body through urine.

Question 26

What is the absorptive state?

Answer 26

The fed state; from the time you eat until 4 hours after.

Question 27

What is the post absorptive state?

Answer 27

The fasting state; the metabolic state when food is no longer the body's source of energy. It relies on stored glucose

Question 28

What happens in the effectors during the metabolic states?

Answer 28

liver cells: making glucose into glycogen adipose cells: making fat muscles: the amount of glycogen is increased

Question 29

What is the basal metabolic rate?

Answer 29

It is the baseline, or standard of comparison that minimizes the effects of such variables. It is the metabolic rate when one is awake, but relaxed.

Question 30

What is Total metabolic rate?

Answer 30

It is the sum of the basal metabolic rate and energy expenditure for voluntary activities, especially muscular contraction

Question 31

What are ketone bodies?

Answer 31

They are produced in the liver from fatty acids during prolonged fasting or low carb intake. used by the brain and muscle as alternative feul

Question 32

What is thermoregulation?

Answer 32

It is the balance between heat production and loss, is therefore a critically important aspect of homeostasis.

Question 33

What are some ways the body increased body temperature?

Answer 33

- shivering - vasoconstriction - increased metabolism via thyroid hormone - behavioral (putting on clothing)