Topic 2.3 Carbohydrates and Lipids

Question 1

Carbohydrates are made of monomers called monosaccharides

Answer 1

ex. Glucose, Fructose, Ribose

Question 2

Monosaccharides are linked together to form larger polymers

Answer 2

Disaccharides: maltose, sucrose, lactose
Polysaccharides: Starch, Glycogen, cellulose

Question 3

Condensation reactions (loose of an OH from a molecule and an O from another molecule)

Answer 3

Monosaccharides are created stuck together with condensation reactions

Question 4

Condensation Reactions

Answer 4

This process produces water (H2O) , and is anabolic which requires ATP energy. They can happen between the OH groups of 1st, 4th, 6th carbons.

Question 5

Hydrolysis Reactions

Answer 5

Polymers are broken apart by hydrolysis reactions. (A water molecule separates the two molecules)

Question 6

Polysaccharides

Answer 6

May have different structures and function due to type of glucose/monomer and the type of link between them.

Question 7

Cellulose

Answer 7

Molecule found in plant cell walls to give them strength. Links B – glucose molecules between the 1st and 4th carbon. This results in a straight, unbranched chain that can be bundled together using hydrogen bonds.

Question 8

Starch

Answer 8

Only made in plant cells. Stores glucose in a way that does not let water get in the cell. Links a-glucose between 1st and 4th carbon. Results in a chain that is not straight

Question 9

Glycogen

Answer 9

Glycogen is found in animals/fungi and acts as an energy storage molecule for glucose (also not osmotically active). Is similar to the branched form of starch, but with more branching and longer branches.

Question 10

Types lipids

Answer 10

Made of monomers called fatty acids and glycerol. They bond together trough condensation reactions to create polymers.

Question 11

Lipids

Answer 11

Lipid fats are used as long term energy storage and found in adipose tissues instead of carbs (short term energy)

Question 12

Body Mass Index

Answer 12

Balance of percentage of fat is optimal. BMI assess a person’s weight in relation to their height in order to determine if they have a healthy/unhealthy amount of fat on their body. BMI = mass (kg)/height2 (m).

Question 13

Types of fatty acids

Answer 13

Saturated fatty acids consist of single bonds. Unsaturated fatty acids contain at least one double bond, these carbons have only one H

Question 14

Unsaturated fatty acids

Answer 14

Mono-saturated fatty acids have one double bond.Polyunsaturated fatty acids have multiple double bonds.

Question 15

Types of unsaturated fatty acids

Answer 15

Oils: Contain CIS fatty acids where the hydrogens are on the same side. Bent molecule that doesn’t pack well and has a lower melting points
Fats: Contain TRANS fatty acids where the hydrogens orient in opposite directions. Straight molecule that can pack together and have a higher melting point.

Question 16

Fatty acids & Health

Answer 16

Coronary heart disease is caused by a build up of fat blocking the arteries. There is a correlation between saturated fat intake and CHD but causation is unsure.There is a positive correlation between trans fat and CHD and some causal proof.

Question 17

Animal Testing (Dietary effects)

Answer 17

Health claims regarding dietary substances are often tested on animals as opposed to humans. 1. Easy to obtain large numbers of genetically uniform animals (same sex, age, state of health, etc.). 2.Variables other than diet are easy to control. 3. Ethical issues arise if the animals may be harmed to prove causality 4. Results may not apply to humans

Question 18

Human Testing (Dietary effects)

Answer 18

Human results can be simultaneously better or worse in terms of reliability. 1. Results are more applicable for other humans. 2. May also face ethical/safety issues. 3. May struggle to prove correlation or causality. 4. Limitations in sample size and evenness of sample (ex: same age/gender/lifestyle) 5. Volunteers may be unreliable

Question 19

Triglycerides

Answer 19

(fats and oils) include three fatty acids and one glycerol