Macronutrition

Question 1

What are the macronutrients?

Answer 1

• carbohydrates
• proteins
• lipids

Question 2

Generally, what are carbohydrates used for?

Answer 2

Carbs are used to generate many metabolic intermediates.

Question 3

What are excess carbohydrates converted into?

Answer 3

• glycogen
• triacylglycerol

Question 4

Classify glucose, fructose, and galactose:

Answer 4

• monosaccharides
• simple carbohydrates

Question 5

Classify sucrose, lactose, and maltose:

Answer 5

• disaccharides
• simple carbohydrates

Question 6

Classify glycogen in animals, and starch & fiber in plants:

Answer 6

• complex carbohydrates

Question 7

What is the most abundant carbohydrate in nature?

Answer 7

cellulose

Question 8

What is the most important carbohydrate fuel for the body?

Answer 8

glucose (dextrose)

Question 9

What is glucose also referred to as?

Answer 9

• dextrose
• blood sugar

Question 10

What blood component increases as a result of fructose consumption?

Answer 10

• blood lipids

Question 11

What contains fructose?

Answer 11

fruits and vegetables

Question 12

Where is a-amylase found?

Answer 12

• saliva
• pancreatic juice

Question 13

What is the function of a-amylase?

Answer 13

• Hydrolyzes starch and glycogen to maltose and maltotriose

Question 14

Which enzymes are found on the luminal surface of the small intestine?

Answer 14

• maltase
• sucrase
• lactase

Question 15

What is the function of maltase?

Answer 15

maltose and matotriose –> glucose

Question 16

What is the function of sucrase?

Answer 16

sucrose –> glucose and fructose

Question 17

What is the function of lactase?

Answer 17

lactose –> glucose and galactose

Question 18

What kind of carbohydrate is the only kind to be absorbed in the body?

Answer 18

monosaccharides

Question 19

How are indigestible carbohydrates metabolized?

Answer 19

• converted to monosaccharides by bacterial enzymes
• metabolized anaerobically by bacteria

Question 20

What is an example of an oligosaccharide in beans and peas that can’t be hydrolyzed by human enzymes?

Answer 20

Raffinose

Question 21

What does glycemic index measure?

Answer 21

how quickly individual foods will raise blood glucose level

Question 22

List examples of dietary fibers?

Answer 22

• cellulose and hemicellulose
• lignin
• pectin

Question 23

What is the function of cellulose (insoluble dietary fiber)?

Answer 23

Cellulose increases stool bulk and decreases intestinal transit time.

unrefined cereals, bran whole wheat

Question 24

What is the function of lignin (insoluble dietary fiber)?

Answer 24

Binds cholesterol and carcinogens

woody parts of vegetables

Question 25

What is the function of pectin (**soluble** dietary fiber)?

Answer 25

Decreases rate of sugar uptake and decreases serum cholesterol | fruits

Question 26

What makes up more than 90% of dietary fat?

Answer 26

Triacylglycerol

Question 27

What is an example of an omega-3 (w-3) fatty acid?

Answer 27

a-linolenic acid (18-3) | vegetable oils

Question 28

What are examples of omega-6 fatty acids?

Answer 28

- linoleic acid (18:2) -- corn oil - arachidonic acid (20:4) -- meat and fish

Question 29

What are essential fatty acids used for in the body?

Answer 29

- Used to synthesize eicosanoids in the body

Question 30

What is the ratio of w-3 to w-6 fatty acids important for?

Answer 30

Regulating processes such as: - blood pressure - blood clotting - immune functions

Question 31

What are the effects of trans fats?

Answer 31

- raise blood cholesterol - increases the risk of heart disease

Question 32

What is required in order for fats to be digested?

Answer 32

- solubilization by bile acids

Question 33

What is the function of gastric and pancreatic lipases for the digestion of lipids?

Answer 33

- hydrolyze triacylglycerol to fatty acids and monoacylglycerol

Question 34

What is the function of esterase?

Answer 34

- Hydrolyzes monoacylglycerol and cholesterol ester

Question 35

How are lipids utilized?

Answer 35

- chylomicrons delivers lipids to peripheral tissues directly - muscles use fat as energy source

Question 36

How is excess fat utilized?

Answer 36

- excess fat is stored in adipose tissues

Question 37

Does the brain use fat as an energy source?

Answer 37

No

Question 38

How are fatty acids utilized in a starved state?

Answer 38

- The liver converts fatty acids to ketone bodies - The ketone bodies are used as an energy source by brain and muscle | ketogenesis

Question 39

How is excess protein utilized?

Answer 39

- source of energy - glucogenic amino acids --> glucose - ketogenic amino acids --> keto acids and fatty acids | eventually converted to triacylglycerol in adipose tissues

Question 40

What induces a negative nitrogen balance?

Answer 40

- inadequate dietary intake of protein - trauma or illnes

Question 41

What induces a negative nitrogen balance?

Answer 41

- inadequate dietary intake of protein - trauma or illness

Question 42

What induces a positive nitrogen balance?

Answer 42

- net increase in body protein stores - growing children, pregnant women, or adults recovering from illness

Question 43

What are the components of gastric digestion of proteins?

Answer 43

- pH of gastric juice < 2 - Low pH denatures proteins - Pepsins - stable and active at acidic pH -- aspartic protease

Question 44

Where are peptidases found?

Answer 44

at the luminal surface and intracellularly

Question 45

What is the energy content of one gram of carbohydrate?

Answer 45

4 kcal

Question 46

What is the energy content of one gram of fat?

Answer 46

9 kcal

Question 47

What is the energy content of one gram of protein?

Answer 47

4 kcal

Question 48

What is glycogen in the liver used for?

Answer 48

maintaining blood glucose levels

Question 49

What is glycogen in the muscle used for?

Answer 49

exercise

Question 50

Under which conditions is insulin released?

Answer 50

Well-fed state

Question 51

Under which conditions is glucagon released?

Answer 51

- Early fasting - fasting

Question 52

When are the cori cycle and alanine cycle in use?

Answer 52

Early fasting state

Question 53

When does lipolysis and ketogenesis occur?

Answer 53

Fasting state

Question 54

How does the brain adapt to starvation?

Answer 54

- It uses ketone bodies that are made from acetyl-CoA in the liver as energy

Question 55

What are the characteristics of marasmus?

Answer 55

- inadequate intake of **protein and energy** | thin wasted appearance

Question 56

What are the characteristics of Kwashiorkor?

Answer 56

- inadequate **protein** but adequate energy | deceptive plump due to edema