Aqa as biology paper 2 unofficial mark scheme

all guessses:

DNA 5 marker: E (eukaryotic)
-in E, longer, in P, shorter
-in E, linear, in P, circular
-in E, histones, in P, supercooling
-in E, in nucleous, in P, cytoplasm
-both contain genetic info

Why are combined actions of enzymes better (2)
-endo hydrolyse internal bonds
-more ends increase SA for external

what is a control for (2)
-comparison with or without IV
-shows substance X caused growth in roots nothing else

Scroll to see replies

Reply 1

flosiphy

cell growth prevention (3):
-chromatids not separate at centromere
-spindle fibres don't contract
-not pulled to oppposite sides
-cannot go into telophase
-disrupts cell cycle

Reply 2

flosiphy

Water and diffusion (2)
-down conc gradient
-passive
-channel proteins for facilitated diffusion

Reply 3

flosiphy

tick Box (3)
B,A,E

Milk (2)
-Golgi vesicles stores lipids and proteins and transports to CSN
-mitochondria produce ATP for active transport

Dipeptides (2)
-Condensation
-Join aminos through peptide bonds
-Release water molecule

Equation (1)
Final Mass divided by Original Over Original times 100

Why do enzymes bind at diff sites (2)
-unique tertiary
-specific active site
-only bind to complementary substrate
-ES complex

Reply 4

flosiphy

Percentage change (2)
3.7%

Diameter (2)
-work out Radius (0.88)
-times by 2
-diameter: 1.76

Reply 5

flosiphy

SA size (1)
-small organsisms have high SA to VOL

Oxygen uptake = metabolic rate (2)
-metabolic: chemical reactions like respiration
-oxygen uptake in respiration
-directly related

Reply 6

flosiphy

antibiotic in Bacteria common (3)
-T antibiotic more common in foods
-few bacteria have alleles for antibiotic resistance through directional selection
-more likely to survive reproduce
-pass onto offspring
-allele frequency increases

Reply 7

flosiphy

Why cannot u conclude? (3/4)
-no data for egg
-weak correlation: no casual relationship
-other factors involved
-one study
-no control group used

Reply 8

flosiphy

why are monoglycerides lipid soluble (2)
-conc external directly proportional to rate of uptake by epithelial cells
-no barrier from limited carrier and channel proteins

Describe Curve AB (2)
-uptake increases rapidly as conc increases but plateaus
-not enough carrier or channel proteins for monosaccharides to use

Reply 9

flosiphy

how does bonds form Secondary protein structure: (2)
-h bonds form between H of NH and O in C=O
-causes folding to alpha helix or beta pleated sheet

same amino she but diff proteins (2)
-diff dna base sequences
-diff amino acid seq
-alters h/ionic/disulfide bonds
-changes tertiary structure

Reply 10

flosiphy

Haemoglobin phonology (5)
-amino acid seq = primary structure
-joined by peptide bonds
-condemnation
-aminos coded by Triplets
-genetic code is universal: same triplets code for same aminos
-shows all organisms derive from same common ancestor

Reply 11

flosiphy

what is digestion (2)
-breaking down polymers
-to monomers to smaller molecules
-enzymes catalyse hydrolyse of chemical bonds
-so can pass membrane easier