Topic 3

Question 1

What are the functions of glucose?

Answer 1

• Converted to glycogen to store energy
• Converted to fat to store energy (long term)
• Oxidized for energy
• Glycoproteins
• Precursor of amino acids C-skeleton
• Prevent ketosis

Question 2

Which tissues/ organs/ processes use glucose for energy?

Answer 2

o Brain, RBCs, mammary gland, fetus, spermatogenesis

Question 3

Describe glycoproteins

Answer 3

o Spontaneous glycation of proteins doesn’t require an enzyme and can damage the function of protein due to agedisturbs the function
o Some proteins have glucose attached to it that need it to function

Question 4

The intestine does not need glucose, but uses __ as a fuel.

Answer 4

The intestine does not need glucose, but uses glutamate as a fuel.

Question 5

WHich cells have an absolute requirement for glucose and why?

Answer 5

• Certain cells have an absolute requirement for glucose, such as the brain and RBCs which do not have any organelles. Therefore, their only source of energy is glucose and glycolysis

Question 6

What an exception from the rule that glucose is a precursor for glucose?

Answer 6

o All of the amino acids that we can make in the body come from glucose EXCEPT for tyrosine (made from phenylalanine which is hydroxylated).
Phenylalanine+ OH-> Tyrosine

Question 7

What is the recommended intake of CHOs?

Answer 7

45-65% of energy intake (1/2-2/3 of our intake)

Question 8

Does glycogen make up a significant part of our diet?

Answer 8

no

Question 9

Why should pregnant women not do keto diet?

Answer 9

GLucose is a major energy source for the fetus

Question 10

Brain needs a __ supply of glucose

Answer 10

Brain needs a constant supply of glucose

Question 11

WHat is the formula for CHO monomer?

Answer 11

Cn(H2O)n

Question 12

Give an example of CHO monomer and it’s weight and formula

Answer 12

Hexoses-> C6H12O6 (FW: 180g)

Question 13

What are the 2 types of bonds in disaccharides?

Answer 13

• Alpha or beta glycosidic bonds
o When Hydrogens on same side-> alpha
o When H on opposite sides, or the bond looks diagonal-> beta

Question 14

List lactose, sucrose, glucose, maltose, fructose in terms of sweetness

Answer 14

o	Fructose (twice as sweet as sucrose) (mono)
o	Sucrose
o	Glucose (mono_
o	Maltose
o	Lactose

Question 15

How do CHOs act as preservatives?

Answer 15

Presence of free sugar ties up free water an minimizes bacterial growth-> preservative

Question 16

Name 2 types of starch units and their bonding

Answer 16

• Amylose alpha (1-4) chains

* Amylopectin alpha (1-4) chains with alpha (1-6) brancheы

Question 17

Name 3 types of fibers, their examples and where they are found

Answer 17

Soluble
o Pectin (found in fruits)
o E.g. oatmeal
Insoluble
o Hemicellulose, cellulose
o E.g. celery
Functional
o Has characteristics of both soluble and insoluble fibre
o Psyllium added to foods—such as cereals to increase fiber intake
o Added as a food additive in processing, related to health-promoting effects

Question 18

Metabolic effects of soluble fiber

Answer 18

• Forms viscous el in the stomach
• Delays gastric emptying-> CHOs are distributed more equally-> slower digested and absorbed
• Binds cholesterol and bile acids
• Fermented by colonic microbiota -> produces organic acids

Question 19

Metabolic effects of insoluble fiber

Answer 19

• Bulk (laxative effect) - - Colon is not going to absorb as much water-> softens stool
• Delays gastric emptying->
  Some glycemic control, but less than soluble fiber
  o Binds cations (phytates are negative and will bind cations such as calcium, zinc, iron-> not desirable due to deficiencies that may arise)
  o Speeds up transit altogether
  o Minor fermentation by colonic bacteria

Question 20

Which bonds does salivary amylase break?

Answer 20

the alpha, 1-4 bonds in starch

Question 21

What is the pH of the stomach

Answer 21

-1

Question 22

What is the level of glucose in blood?

Answer 22

usually 5 mmol/L

4g in our blood at any time

Question 23

Hypoglycemia- what are the conditions and effects on the brain

Answer 23

blood glucose below 4g-? around 2g in the brain- > very low

Question 24

Hyperglycemia- characteristic

consequences

Answer 24

10 mmol/L

Dehydration- water is excreted