idk

Question 1

what would a high Ph do to the phospholipid bilayer

Answer 1

at a low ph, the cell is more acidic, there are more H+ ions which disrupt the cell membrane
H+ ions denature the proteins in the cell membrane so dirupt the phospholipid bilayer, IONIC BONDS ARE AFFECTED HERE, the permability of the cell increases

Question 2

what does the nucleolus make

Answer 2

ribosomes

Question 3

how do monocytes become macrophages

Answer 3

when they move into tissues

Question 4

what way does dna polymerase move

Answer 4

5’ to 3’

Question 5

State and explain ways in which the glucose molecule is well suited to its function in
living organisms.

Answer 5

• soluble so can be transported easily
• easily broken down and respired to release energy
• small so can be transported across cell membranes
• molecules can be transported to produce polysaccharides

Question 6

size of ribosomes in humans and bacteria

Answer 6

humans= 80s
bacteria= 70s

Question 7

What do fatty acids donate

Answer 7

H+ ions

Question 8

talk abt unsaturated fatty acids

Answer 8

• contain more than one C=C bond
• kinking means that unsaturated fatty acids cant pack as closely together, making intermolecular forces weaker, less energy to break the intermolecular forces

Question 9

talk abt how triglycerides are good energy sources

Answer 9

• the ester bonds can be easily hydrolysed to release glycerol for respiration, they act as energy stores.

Question 10

talk abt what happens during the formation of a peptide bond

Answer 10

• the carboxyl group donates an -OH group while the amino acid donates an -H to form a peptide bond, and a molecule of water is produced

Question 11

what is used to break down non-reducing sugars

Answer 11

hydrochloric acid

Question 12

low reading of absorbance=

Answer 12

Low reading for absorbance means higher conc. of reducing sugar

Question 13

what is used to test for starch

Answer 13

potassium iodide

Question 14

example of increasing validity

Answer 14

use colorimeter instead of colourchart

-look at experiment design

Question 15

how to improve accuracy

Answer 15

take a mean

• more points
• anomalies

Question 16

triphosphates release energy for what

Answer 16

formation of phosphodiester bonds

Question 17

what is amylase secreted by

Answer 17

the salivary glands and the pancreas

Question 18

Q10 coefficient

Answer 18

rate at T + 10
__________
rate at T

Question 19

what are there subtle changes in in the induced fit

Answer 19

subtle changes in the R group

Question 20

what will a high pH do to enzymes

Answer 20

will disrupt the hydrogen and ionic bonds causing changes in the tertiary structure

Question 21

Explain how a change in a sequence of DNA bases could result in a non-functional enzyme.

Answer 21

• different amino acid sequence
• different R groups on the amino acids so different bonds form
• so change in tertiary structure so different active site which won’t be complimentary to substrate

Question 22

Explain how cell surface membranes contribute to the process of cell signalling.

Answer 22

• cells release molecules for signalling from cells through exocytosis.
• glycoproteins act as receptors.
• specific receptors on plasma membrane will receive the molecules.
• as molecules and receptors are complimentary to each other

Question 23

How would using a narrower range of alcohol concentrations improve the investigation?

Answer 23

would improve accuracy

Question 24

how are the gills adapted for efficient gas exchange?

Answer 24

• many lamella provide a large surface area
• secondary lamellae provide for a large sa to volume ratio
• this allows for faster diffusion
• there is also a short distance between blood and water

Question 25

whats a tissue

Answer 25

• a collection of the same cells providing the same function

Question 26

whats an organ

Answer 26

-made up of several different tissues to perform a function

Question 27

talk abt what competitive inhibitors do

Answer 27

• competes with substrate for active site
• both complimentary
• it blocks the active site
• substrate now cant enter and form an esc

Question 28

what bonds does a high pH disrupt

Answer 28

disrupts ionic and hydrogen

Question 29

why is vaccination active immunity

Answer 29

• activation of lymphocytes occur
• antibodies are produced
• memory cells remain

Question 30

3 properties of fibrous compared to globular

Answer 30

• insoluble
• unreactive
• strong

Question 31

when doing a test what should always be present

Answer 31

a control

Question 32

why have bats and birds both evolved wings

Answer 32

they have a simmilar niche

• both face simmilar selection pressures
• wings are an advantage to survival so allele is to be passed on

Question 33

outline the process of DNA rep after pairing of nitrogenous bases

Answer 33

• DNA polymerase bind nucleotides together
• sugar phosphate backbone reforms
• DNA winds into a double helix

Question 34

cell mediated immunity- what happens

Answer 34

Action of T cells

• antigen is presented via host cell
• T cells with correct receptor bind with antigen
• they divide by mitosis (clonal expansion) and differentiate into T4

Question 35

humoral immunity- what happens

Answer 35

Action of B cells

• A free antigen binds to a complimentary B cell receptor, activating the B cell (clonal selection)
• the pathogen is endocytosed and presented on the PM
• T helper cells bind to the presented antigens and stimulates the B cell to divide by mitosis (clonal expansion)
• the B cell differentiates into plasma cells and memory cells