Nutrients & their Metabolism

Question 1

What are the important dietary CHO categorised into?

Answer 1

Monosaccharides

Disaccharides + oligosaccharides

Polysaccharides

Question 2

How many carbons can monosaccharides have?

Answer 2

3 to 7

Question 3

What are the most important monosaccharides?

Answer 3

The 6C hexoses:

• Glucose
• Galactose
• Fructose

Question 4

What is the most important monosaccharide

Answer 4

alpha-D-glucose

Question 5

What is the sweetest monosaccharide?

Answer 5

Fructose

Question 6

How is high fructose corn syrup manufactured enzymatically?

Answer 6

By changing the glucose in cornstarch to fructose.

Question 7

What does evidence suggest about high fructose corn syrup?

Answer 7

That high diets of this may contribute to obesity + other health conditions i.e metabolic syndrome.

Question 8

Where are galactose + fructose metabolised?

Answer 8

Liver

Question 9

What do infants have when they are born with inability to metabolise galactose?

Answer 9

Galactosemia

Question 10

What are the 3 most important disaccharides

Answer 10

Sucrose

Lactose

Maltose

Question 11

How are disaccharides formed?

Answer 11

By glycosidic linked monosaccharides between the active aldehyde or ketone carbon + a specific hydroxyl on another sugar.

Question 12

Describe what an invert sugar is

Answer 12

A natural form of sugar

An unlinked glucose + fructose in a 1:1 ratio

Question 13

Why is invert sugar used commercially?

Answer 13

Sweeter than the equal conc. of sucrose.

Question 14

Give an example of an invert sugar

Answer 14

Honey

Question 15

What are oligosaccharides

Answer 15

Small 3-10 monosaccharide

Readily H20 soluble

Often sweet

Question 16

Define a polysaccharide

Answer 16

CHO w/ 10+ monosaccharide units

Question 17

Why is amylopectin more abundant in the food supply than amylose?

Answer 17

Due to its larger size

Question 18

What causes different starches to have their own unique taste, texture + absorbability?

Answer 18

The rel. no. of glucose units in straight (amylase) and branched configurations (amylopectin)

+

The degree of accessibility to digestive enzymes.

Question 19

What does moist cooking cause for the starch granules?

Answer 19

Causes them to swell

= Gelatinises the starch, softens + ruptures the cell wall

= Making starch more digestible by pancreatic amylase.

Question 20

Define dietary fibre

Answer 20

Intact plant components

GI enzymes can’t digest

Question 21

Define functional fibres

Answer 21

Nondigestible CHO that have been extracted or manufactured from plants

Question 22

List some of the less soluble fibres

Answer 22

Cellulose

Hemicellulose

Lignin

Question 23

Major function of cellulose as a less soluble fibre

Answer 23

⬆️ H20-holding capacity = ⬆️ fecal volume + ⬇️ gut transit time.

Question 24

Major function of lignin as a less soluble fibre

Answer 24

Fermentation produces short-chain FAs associated w/ ⬇️ risk of tumor formation

Question 25

List some of the more soluble fibres

Answer 25

Gums Pectins

Question 26

Major function of gums being a more soluble fibre

Answer 26

Cause gel formation = ⬇️ gastric emptying, slow digestion = slow gut transit time + glucose absorption

Question 27

Major function of pectins as a more soluble fibre

Answer 27

Binds minerals, lipids + bile acid = ⬆️ excretion of each = ⬇️ serum cholesterol

Question 28

What is the major function of the more functional fibre Fructans

Answer 28

Prebiotic that stimulates growth of beneficial bacteria in gut Used as a fat replacer

Question 29

Approx what % of the human diet do fats + lipids constitute?

Answer 29

34%

Question 30

Where is dietary fat stored in the human body?

Answer 30

Adipose cells

Question 31

What is structural fat?

Answer 31

Fat deposits that aren't used effectively during a fast.

Question 32

What type of fat holds the body organs + nerves in position and why?

Answer 32

Structural fat pads To protect them vs traumatic injury + shock.

Question 33

What do structural fat pads on the palms + buttocks do?

Answer 33

Protect the bones from mechanical pressure

Question 34

What is dietary fat essential for?

Answer 34

The digestion, absorption + transport of fat-soluble vitamins + phytochemicals. Depresses gastric secretions Slows gastric emptying Stimulates biliary + pancreatic flow == Facilitating digestion

Question 35

Give some examples of photochemicals

Answer 35

Carotenoids Lycopenes

Question 36

Length of chains + number of bonds for the fats that are liquid at room temp

Answer 36

Shorter chains More double bonds

Question 37

Solid at room temp fats?

Answer 37

Sat fats Long chained

Question 38

What type of fat is coconut oil

Answer 38

A highly saturated fat

Question 39

What state is coconut oil in at room temp? Why?

Answer 39

Semiliquid Due to the predominant FA being short (8-14C).

Question 40

Binding sites on a sat FA

Answer 40

All C binding sites nOT linked to another C are linked to H + are therefore saturated.

Question 41

How many double bonds do monounsaturated FA have?

Answer 41

1

Question 42

How many double bonds do polunsat FA have?

Answer 42

2 or +

Question 43

Describe the omega notation convention used to describe the location of double bonds

Answer 43

Lower case omega (w) or n is used to refer to the placement of the 1st double bond counting from the METHYL end.

Question 44

What can only plants synthesise?

Answer 44

Omega-6 FA Omega-3 FA

Question 45

What are aa

Answer 45

Carboxylic acids w/ an amino group attached to the alpha-C

Question 46

Negative effects of alcohol

Answer 46

Depression Gi tract irritant Foetal development issues Weightgain

Question 47

By which method is vitamin C absorbed?

Answer 47

Active transport

Question 48

Where is vitamin c stored?

Answer 48

Pituitary + adrenal glands WBC Eyes Brain

Question 49

What can vitamin D to phosphorus?

Answer 49

⬆️ its absorption

Question 50

Where is vitamin E stored?

Answer 50

Adipose tissue