Chap 5 and part of 8

Question 1

Monosaccharides

Answer 1

(simple carbs) 1 sugar unit

• glucose
• fructose
• galactose

Question 2

Disaccharides

Answer 2

(simple carbs (2 sugar units)
2 monosaccharides bound by a condensation bond.
Alpha and beta

Question 3

oligasaccarides

Answer 3

Complex sugar (3-10 units of sugar= saccharides)
e.g. raffinose and stachyose
mainly indigestible, may cause discomfort

Question 4

polysaccharides

Answer 4

Complex sugars (>10 units)
many monosaccharides bound
starch, glycogen, cellulose and fibre
digestibility depends on alpha and beta glycosidic bonds

Question 5

Sucrose

Answer 5

glucose + fructose

alpha 1,2 glycosidic bond

Question 6

Monosaccharides

Answer 6

(simple carbs) 1 sugar unit 
6 carbon single unit: 
- glucose 
- fructose 
- galactose 
sugar alcohols: Xylitol, mannitol and sorbitol
5 carbon single unit: 
Ribose 
deoxyribose

Question 7

Maltose

Answer 7

glucose + glucose
alpha 1,4 glycosidic bond
C12 H22O11

Question 8

Verbacose

Answer 8

glucose + galactose + Fructose

Question 9

complex carbohydrates

Answer 9

Oligosaccharides and polysaccharides

starch, glycogen and fibre

Question 10

Simple Carbohydrates

Answer 10

monosaccharides and disaccharides

Question 11

Carbohydrates
chemical structure

roles

Answer 11

chemical structure:
Carbon, hydrogen and Oxygen
monomer= saccharide
produced by plants via photosynthesis (glucose)
roles:
basis of structural tissue found in plants
source of energy and blood glucose homeostasis. Substrate in the biosynthesis of other compounds.
cell to cell recognition and communication: saccharides used in formation of glycoproteins that sit on surface of cells.

Question 12

glucose

Answer 12

C6H12O2
Most abundant monosaccharide
consumed as sucrose (glucose + fructose)
Most of glucose cell uptake is insulin dependent via glucose transporter 4 (GLUT 4)
glucose uptake by liver is not insulin dependent

Question 13

Lactose

Answer 13

galactose + glucose
beta 1, 4 glycosidic bonds
milk sugar

Question 14

Type 1 diabetes

Answer 14

Autoimmune disease 
beta cells of pancreas are destroyed- no insulin produced 
symptoms: 
excessive urination 
dehydration/ thirst 
thrush/ genital itching 
slow to heal wounds 
blindness/ blurred vision 
tired/ lethargic 
weight loss 
treatment: drugs

Question 15

Type 2 diabetes

Answer 15

Lifestyle related
either not enough insulin is produced/ cells aren’t responding as well to insulin. pancreatic beta cells are exhausted/ fail
glucose levels in blood rise/ insulin levels rise
symptoms:
excessive urination
thirst
blurred vision
tiredness
weight loss
treatment: diet/ lifestyle changes- drugs.

Question 16

Alcohol metabolism

Answer 16

3 pathways

1. alcohol dehydrogenase
2. MEOS
3. catalase

all produce Acetaldehyde—> (aldehyde dehydrogenase) –> acetyl CoA– > citric acid cycle.

Question 17

Standard drink in Aus

Answer 17

10g of alcohol

Question 18

what is standard drink based on

Answer 18

assumption that the liver metabolises 10g of alcohol per hour (varies between 5-10 g depending on body size and sex)

Question 19

specific gravity of alcohol

Answer 19

0.789

Question 20

specific alcohol in a drink

Answer 20

ml * % * specific gravity of alcohol

Question 21

Standard drinks

Answer 21

specific alcohol divided by ten.

Question 22

Fructose

Answer 22

Carbonyl group on the C-2 not the C-1.
sweetest monosaccharide
cell uptake is not insulin dependent!
large consumption linked with fatty liver disease (doesn’t require any transporters- therefore taken up easier by the body, the pathway to glyceraldehyde (2steps Verse 4)
therefore the pool of pyruvate is increased much faster with fructose. Exess goes to fatty acid synthesis for storage.

Question 23

Is honey a healthier option

Answer 23

no. still contains plenty of carbs.

Question 24

indigestible polysaccharides

Answer 24

Fibre

Question 25

Fibre

Answer 25

The fraction of the edible part of the plant, or their extracts, or analogous carbohydrates that is resistant to digestion and absorption in the human intestine, usually with complete or partial fermentation in the large intestine by bacterial colonies. (cellulose beta bond, and starch alpha bond)

Question 26

Fibre

Answer 26

The fraction of the edible part of the plant, or their extracts, or analogous carbohydrates that is resistant to digestion and absorption in the human intestine, usually with complete or partial fermentation in the large intestine by bacterial colonies. (cellulose beta bond, and starch alpha bond) sources: cell walls on plants, seed coats (bran) of cereals, Structural components of fruit, nuts and vegetables, roots vegetables Microbiological, fungal or animal components (e.g. body shell and exoskeletons)

Question 27

soluble fibre

Answer 27

(type of dietary fibre) Pectin, gum, mucilage and some hemicellulose

Question 28

insoluble fibre

Answer 28

(source of dietary fibre) doesn't change in the presence of water. cellulose, hemicellulose and lignins

Question 29

Galactose

Answer 29

diifers with glucose by orientation around the C4. converted to glucose in the liver ( by the enzyme galactokinase) + glucose= lactose the least sweet monosaccharide

Question 30

Galactocymia

Answer 30

reduction in the metabolism of galactose to glucose. - deficiency in the enzyme galactokinase or other metabolic genes. galactose build up leads to bacterial infections, mental retardation and cataracts. must avoid foods that contain it - milk products - organ meats - some fruit, nuts and veg.

Question 31

Galactocymia

Answer 31

reduction in the metabolism of galactose to glucose. - deficiency in the enzyme galactokinase or other metabolic genes. galactose build up leads to bacterial infections, mental retardation and cataracts. Perceived early on in life. must avoid foods that contain it - milk products - organ meats - some fruit, nuts and veg.

Question 32

Sugar alcohols

Answer 32

derivatives of mono, di or polysaccharides. Class of polyols, 1 OH group attached to each carbon Primarily used as low energy sweeteners because not fully absorbed in small intestine. In the colon, fermented by bacteria (produces gas) May induce bloating, diarrhoea and flatulence with large quantity as water is drawn into the colon, and bacterial fermentation Occur naturally in many fruit and vegetables (extracted from birch tree, corn cobs), but usually issued from hydrogenation of sugars (sorbitol, mannitol, xylitol), or via fermentation of sugars (erythritol) for commercial purposes Xylitol, adonitol, Dulcitol.

Question 33

Discuss the pros and cons alternative sweeteners that may replace sugar and caloric sweeteners

Answer 33

Artifitial sweetners they are much sweeter. Pros: in context of type 2 diabetes and obesity: don't contibute to blood sugar levels, don't contribute to caloric intake cons: consumed in excess may produce lots of gas, bloating, diarrhoea

Question 34

Discuss the pros and cons alternative sweeteners that may replace sugar and caloric sweeteners

Answer 34

Artificial sweetners they are much sweeter. Pros: in context of type 2 diabetes and obesity: don't contribute to blood sugar levels, don't contribute to caloric intake cons: link b/w sweetners and promoting bad bacteria= bad gut microbiota= metabolic effects psychological response: saving calories to eat more things.

Question 35

Pentose monosaccharides

Answer 35

(makes supply via pentose phosphate pathway) ribose and deoxyribose contain 5 Carbon Are an essential part of the cells genetic material- ribose (RNA) deoxyribose (DNA) also found in food: nuts, meat, dairy, vegetables, and it is part of riboflavin

Question 36

Lactose intolerance Primary/ secondary symptoms solution

Answer 36

inability to digest lactose (dosage dependent) primary: shortage of the enzyme lactase in adulthood because of the lactase non-persistence. which is the default post weaning. secondary: in lactose persistent phenotypes (ethnicities and pop with farming ancestry) it is associated with damage of the lactase producing cells. symptoms: Nausea, Cramps, distention, gas, diarrhoea symptoms last 30min- 2 hrs post consumption. solutions: take enzyme lactase zygomil: has enzymes already in the milk to aid digestion

Question 37

Amylose

Answer 37

all bonds between molecules are 1-4 alpha bonds. Alpha bonds= straight row. continuous chain of glucose molecules linked by α-1,4 glycosidic bonds

Question 38

amylopectin

Answer 38

All bonds between molecules 1-4 alpha bonds, except where the molecule branches. branched chain of glucose molecules linked by α-1,4 and α-1,6 glycosidic bonds. More quickly digested as more sites available to enzymes activity