TOPIC 2

Question 1

Monomer

Answer 1

A simple compound whose molecules can join together to form polymers

Question 2

Polymer

Answer 2

A large molecule consisting of many identical or similar monomers linked together

Question 3

Monosacccharides

Answer 3

Monomers linked together by condensation reactions to form disaccharides and polysaccharide polymers, monomers of polysaccharides

Question 4

Disaccharide

Answer 4

Two monosaccharide monomers joined via glycosidic linkage to form a disaccharide.

Question 5

Polysaccharide

Answer 5

Polysaccharides (many sugar units) may be used for energy storage or cell structure, and also play a role in cell recognition. Many monosaccharide monomers may be joined via glycosidic linkages to form polysaccharides

Question 6

Outline primary structure proteins

Answer 6

• The order / sequence of the amino acids of which the protein is composed
• Controls all subsequent levels of structure
• Formed by covalent peptide bonds between adjacent amino acids
• fibrous

Question 7

Outline secondary structure

Answer 7

• Amino acid sequences folding into two stable configurations, called secondary structures, either Alpha helices or beta - pleated sheets
• Due to hydrogen bonds between amine and carboxyl group
• Structural stability
• fibrous

Question 8

Tertiary structure

Answer 8

• The overall three-dimensional configuration of the protein
• Caused by and depends on properties and interactions between R groups (eg, hydrophilic R groups on outside, hydrophobic fold inwards)
• important for function
• globular

Question 9

Quaternary structure

Answer 9

• One or more polypeptide chains folded
• Interaction between multiple polypeptides or prosthetic groups
• Inorganic compound involved in proteins
• globular

Question 10

Contrast lipids and carbohydrates

Answer 10

PRO LIPIDS:
- the energy released by lipids is double that of carbohydrates
- they also add 1/6 as much body mass as carbs
- therefore overall more efficient

PRO CARBS:
- glycogen can be broken down into glucose rapidly, whereas fats in adipose tissue are harder to break down
- glucose can be used in anaerobic respiration or aerobic
- fats can only be used in aerobic respiration

Question 11

Contrast energy storage capabilities of glycogen and glucose

Answer 11

Glycogen has medium term energy storage. It is stored in the liver and muscles and is more readily available than fat.

Glucose is stored in the bloodstream for immediate use. I tis used in respiration for energy or converted to glycogen/fats

Question 12

How do you calculate BMI

Answer 12

mass over height in cm squared

Question 13

Give examples of monosaccharides

Answer 13

Glucose
- hexagonal ring
- fuels respiration
- 5 carbons in ring, 6th corner taken by O

Galactose
- same formula, only difference in placement of H and Os (isomer)
- found

Fructose
- pentsose, 5 carbons

Ribose
- pentose
- forms backbone of RNA

Question 14

Provide a word equation for formation of disaccharides and draw one

Answer 14

monomer +monomer —-> disaccharise + water

glucose + glucose —–> maltose + water
This is a condensation reaction. Water is removed and the two monomers form a glucosidic bond (oxygen bond(

Question 15

Give examples of disaccharides

Answer 15

Maltose
- dimer of glucose

Lactose
- dimer of glucose and galactose

Sucrose
- dimer of glucose and fructose

Question 16

Distinguish between 1-4 and 1-6 bonds with explanation and drawing

Answer 16

• start counting at right corner
• 1-4 bonds form straight chains
• 1-6 form bent, or are responsible for branching

Question 17

Give examples of polysaccharides and distinguish between them

Answer 17

cellulose
- 1-4 C bonds
- straight
- unbranched

amylose
- 1-4 C bonds
- bent
- branched

amylopectin
- 1-4 and 1-6 bonds
- bent
- branched

glycogen
- 1-4 and 1-6 bonds
-bent
- branched

Question 18

What makes up triglycerides?

Answer 18

Glycerol and three fatty acids

Question 19

What are lipids? What are their different types?

Answer 19

• Lipids are glycerol combined with 1,2, or 3 fatty acids (form ester bonds)
• triglycerides, steroids and phospholipids

Question 20

Draw standard structure of amino acid

Answer 20

draw, remember second carbon

Question 21

Outline the key features of carbohydrates

Answer 21

• contain carbon, hydrogen and oxygen
• Organic compounds consisting of one or more simple sugars
• Their monomers follow the general basic formula (CH2O)x
• Their monomers are commonly ring shaped molecules

Question 22

Outine the key features of lipids

Answer 22

• contain carbon, hydrogen and oxygen
• insoluble in water but soluble in nonpolar organic solvents

Question 23

Outline the key features of nucleic acids

Answer 23

contain carbon, hydrogen, oxygen, nitrogen and phosphorus
Chains of subunits called nucleotides, which consist of base, sugar and phosphate groups covalently bonded . If sugar is ribose DNA is formed, if deoxyribose, RNA is formed

Question 24

What makes water a useful coolant?

Answer 24

It has high latent heat of vaporization and specific heat capacity therefore, when it evaporates, it absorbs heat and acts as a coolant

Question 25

Distinguish between cohesion and adhesion

Answer 25

Cohesion refers to the hydrogen bonds between water molecules, while adhesion is the hydrogen bonds between water molecules and other polar molecules

Question 26

Explain how hydrogen bonding affects the force of cohesion.

Answer 26

Cohesion Hydrogen bonding is when the positive end of one water molecule is attracted to the negative end of the other. It allows for droplets to form, as the forces pull water into the smallest possible volume. It also allows for surface tension, because cohesive H bonding resists objects trying to penetrate the surface. Adhesion The strength of the hydrogen bonds allws water to flow in opposition to gravitational forces

Question 27

State two examples of disaccharides

Answer 27

fructose + glucose --> sucrose glucose + galactose --> lactose

Question 28

Outline the difference between an saturated and unsaturated fatty acid

Answer 28

Saturated has no double bonds, unsaturated has double bonds

Question 29

Explain the health risks of trans fats and saturated fatty acids in the diet.

Answer 29

Trans fats and saturated fatty acids may contribute to coronary heart disease by clogging arteries with plaque.

Question 30

Write the word equation for the condensation reactions that would produce a triglyceride lipid from its four molecular subcomponents.

Answer 30

glycogen + three fatty acids = triglyceride + 3H20

Question 31

State how the amino acid sequence in polypeptide is determined.

Answer 31

By the order of deoxyribose bases on DNA

Question 32

Define the term ‘proteome’.

Answer 32

The proteome is the totality of proteins expressed within a cell, tissue or organism at a certain time.

Question 33

Outline Insulin

Answer 33

- globular - protein produced by the pancreas and triggers a reduction in blood glucose levels

Question 34

Outline rhodospin

Answer 34

- Fibrous - A pigment in the photoreceptor cells of the retina that is responsible for the detection of light

Question 35

Outline collagen

Answer 35

- Fibrous - Gives strength to tendons, ligaments, skin and blood vessel walls. - Tensile strength and structure

Question 36

What is the ideal temperature for proteins to function?

Answer 36

35 - 37 degrees Celsius

Question 37

What is denaturation?

Answer 37

When a protein loses is structure and therefore function.

Question 38

what is similar about cis and trans isomers

Answer 38

- both contain, C, H and O - Both have carboxylic groups - both form chains

Question 39

what is different about cis and trans isomers?

Answer 39

- cis is bent, trans is straight - cis has both hydrogen on the same sides of central carbon atom, while trans has them on opposing sides

Question 40

Why can water dissolve solvents?

Answer 40

The polar attraction of large quantities of water molecules can sufficiently weaken intermolecular forces and dissolve any substance that contains charged particles or electronegative ions

Question 41

Name substances transportable in blood

Answer 41

NaCl Oxygen (by hemoglobins) Amino acids (in ionised state) Lipids (when form complexes with proteins)

Question 42

Distinguish between catabolism, anabolism and metabolism

Answer 42

Metabolism is all the chemical reactions that take place in an organism. Catabolic reactions describe the set of metabolic reactions that break complex molecules down into simpler molecules, while anabolic reactions describe the set of metabolic reactions that build up complex molecules from simpler ones.

Question 43

Which fats are better in diet than others?

Answer 43

Unsaturated fats are the healthiest, they raise good cholesterol levels. Trans fats are the worst, they have increased risks of coronary heart disease, as they raise bad cholesterol levels. Evidence to support this is increased rate of CHD, however, counter claim is community is Maasai, Kenya.

Question 44

Examples of foods

Answer 44

unsaturated: olive oil saturated: butter trans: margarine

Question 45

distinguish between methane and water

Answer 45

Water is polar and forms hydrogen bonds, while methane is non polar. Therefore, water absorbs more heat before changing state and has higher melting point, specific heat capactiy and latent heat of vapourisation.

Question 46

An example of an anabolic reaction

Answer 46

Glucose into maltose (a dimer of glucose, a disaccharide). Also condensation.

Question 47

An example of a catabolic reaction

Answer 47

Cellulose (polysaccharide) catabolises into glucose (monosaccharide). Also hydrolysis.

Question 48

Why is cohesion important?

Answer 48

Explains water's high surface tension, which means smaller organisms can move along its surface and it can resist low levels of external force. Also explains why water can movie in a column in vascular tissue plants.

Question 49

Why is adhesion important?

Answer 49

Water's adhesion to other polar surfaces explains its capillary action. It can oppose gravitational force and move upwards in vascular tissue in plants in a transpiration stream (capillary action).

Question 50

Why is water's high specific heat capacity important?

Answer 50

Water can absorb or give off heat without changing its temperature much, which means it is a temperature stabiliser, important for life, because most of the body is made of water so it is temperature stabilising.

Question 51

Why is high heat of vaporization important?

Answer 51

The high heat of vaporization means water can absorb a lot of heat before it vaporizes. This makes it an effective coolant, like sweat in humans. The body is being cooled of the heat that turned the water from liquid into vapour.