term 1

Question 1

Test for lipids

Answer 1

emulsion test

Question 2

Describe the emulsion test

Answer 2

shake substance with ethanol in test tube. THEN ADD WATER- WHITE/MILKY EMULSION=lipid present
*the more cloudy an emulsion, the more lipid present

Question 3

What is a phospholipid made of?

Answer 3

2 fatty acid + a phosphate group+ glycerol

Question 4

Describe the properties of the components of a phospholipid

Answer 4

phosphate group is hydrophilic

fatty acid is hydrophobic

Question 5

name of bonds in fats

Answer 5

ester bonds

Question 6

lactose = monosaccharide x + ——-

Answer 6

alpha glucose + galactose

Question 7

test for starch

Answer 7

iodine added= blue/black if starch present

Question 8

maltose=

Answer 8

alpha glucose + alpha glucose

Question 9

bonds in polysaccharides

Answer 9

glycosidic bonds

Question 10

sucrose=

Answer 10

glucose = fructose

Question 11

test for glycosidic bonds

Answer 11

Benedict’s reagent + heat in water bath. red precipitate formed

Question 12

3 ways active transport differs to facilitated diffusion.

Answer 12

Uses energy / ATP;
Against concentration gradient / low to high concentration;
Does not use channel proteins / only uses carrier proteins;

Question 13

name the different components of a cell membrane

Answer 13

glycolipids
glycoproteins
cholesterol
proteins 
phospholipids

Question 14

properties of lipids

Answer 14

Waterproof-waxy cuticle
Insulation- fat slow conductors of heat -stored below skin + HELP TO RETAIN HEAT
Protection- around kidneys
Source of energy- when oxidised lipids hydrocarbon fatty acid tails provide more than twice the energy as the same mass of carbohydrates and release water
insoluble-trigyclerides

Question 15

polypeptides=

Answer 15

proteins

Question 16

describe competitive inhibition

Answer 16

molecule has similar shape to substrate
binds to active site
prevents substrate from binding= LESS SUBSTRATE ENZYME COMPLEXES

Question 17

The epithelial cells that line the small intestine are adapted for the absorption of glucose. Explain how.

Answer 17

1. Microvilli;
2. Large/increased surface area;
3. Many mitochondria;
4. (Mitochondria/respiration) produce ATP / release or provide energy (for active transport);
5. Carrier proteins for active transport;
6. Channel / carrier proteins for facilitated diffusion;
7. Co-transport of sodium (ions) and glucose or symport / carrier protein for sodium (ions) and glucose;
8. Membrane-bound enzymes digest disaccharides / produce glucose

Question 18

Hydrogen bonds are important in cellulose molecules. Explain why.

Answer 18

1. Holds chains/cellulose molecules together/forms cross links between chains/cellulose molecules/forms microfibrils;
2. Providing strength/rigidity (to cellulose/cell wall);
3. Hydrogen bonds strong in large numbers;

Question 19

A starch molecule has a spiral shape. Explain why this shape is important to its function in cells.

Answer 19

Compact/occupies small space/tightly packed;

Question 20

What is the evidence haemoglobin has a quaternary structure?

Answer 20

MORE THAN ONE POLYPEPTIDE CHAIN

Question 21

The total number of bases in the DNA of the α-polypeptide gene is more than 423. Give two reasons why there are more than 423 bases.

Answer 21

3. Two chains/a non-coding strand/complementary base
   pairs;
4. Addition of base by mutation;

Question 22

The haemoglobin in one organism may have a different chemical structure from the haemoglobin in another organism. Describe how.

Answer 22

Different primary structure/amino acids

Question 23

WHY ARE TEM BETTER THAN SEM

Answer 23

Higher resolution

Question 24

DESCRIBE induced fit model

Answer 24

Active site / enzyme not complementary; Active site changes (shape) / is flexible;
(Change in enzyme allows) substrate to fit / E-S complex to form;

Question 25

what does the lock and key model state which is different to the induced fit?

Answer 25

active site doesn't change shape and is complementary before binding

Question 26

iodine tests for what?

Answer 26

starch

Question 27

What is phosphorylation?

Answer 27

The addition of a phosphate (inorganic) molecule in order to make a substance more reactive

Question 28

What do the bonds between phosphate groups do?

Answer 28

They store energy

Question 29

Why atp a better immediate energy resource compared to glucose

Answer 29

1) Atp hyrdolsyis is one stage so energy is released in a single stage 2) atp releases energy in small quantitive amounts which means that the energy is more manageable to use in comparison to glucose which releases so much energy at once 3) has unstable bonds between phosphate groups

Question 30

The bonds between phosphate groups are...

Answer 30

Unstable meaning that they break easily hence they have a low activation energy

Question 31

3 ways in which a phosphate molecule is gained

Answer 31

* Substrate level phosphorylation- where phosphate molecule is given by a donor molecule in a plant or animal * Photophosphorylation where the phospahte molecule is gained in a chlorophyll containing plant during photosynthesis * oxidative phosphorylation when a phosphate molecule is gained during respiration in an animal or plant cell

Question 32

Atp is used in which processes_ | MASAM

Answer 32

``` Movement Metabolic Activation energy Secretion Active transport ```

Question 33

Name the different ions -SHIP

Answer 33

* Sodium ions help co-transport molecules of either glucose or amino acids with it * Iron ions are important in haemoglobin. Haemoglobin is made up of 4 polypeptide chains each with a Fe2+ ion in the centre which binds to the oxygen in haem so when this does happen fe2+ ion temporarily becomes fe3+ ion until oxygen is released * phosphate ions attach to other molecules to form a phosphate group where dna rna and atp all contain phosphate groups. The bonds between phosphate groups store energy. The phosphate groups in rna and dna allow nucleotides to join up and form polynucleotides * hydrogen ions- determine ph

Question 34

What provides energy for cellular reactions?

Answer 34

ATP

Question 35

The more h+ ions the more a...

Answer 35

Acidic the solution

Question 36

Phosphate groups exist within

Answer 36

ATP, DNA, RNA