End Of Year To Learn Flashcards
Suggest and explain why the combined actions of endopeptidases and exopeptidases are more efficient than exopeptidases on their own
Endopeptidase hydrolyses internal peptide bonds
Exopeptidase hydrolyses bonds at the end
This increases the surface areas and creates more ends for the exopeptidase to hydrolyse increasing the ends
What is an appropriate unit ti use to compare the distribution of stomata on leaves?
Mm2
What are two xerophytic features that plants may have
Small leaves/spines- reduces surface area: volume ratio causing reduced water loss through transpiration
Layer of hairs on surface of leaves- ‘trap’ water vapour decreasing water potential gradient
Why is the rate of water uptake not the same as the rate of transpiration?
Water is sued for photosynthesis
Water is used for respiration
Water is used for turgidity/support
Why can some species live in rivers/lakes but not in the ocean?
Water potential is higher in the species than the water. This creates water potential gradient causing water to leave the species by osmosis causing the species to die
Why is an increase in phosphate linked to the growth of the embryo?
Makes up lots of biological molecules including
DNA/RNA/ATP
Also makes up phospholipid bilayer in cell membrane
Why does the ventilation rate decrease with age?
Less elasticity of lung tissue
Internal intercostal muscles less effective
What evidence might show that interphase has occurred?
Chromosomes visible
Chromosomes had condensed around histones
DNA replicated forming sister chromatids
What is a homologous pair
Pair of chromosomes that carry the same genes
Difference between prokaryotic DNA and linear DNA
DNA is linear in humans, circular in prokaryotes
Human DNA is condensed around histones
How does formation of enzyme-substrate complexes increase the rate of reaction
Reduces activation energy
Due to bending bonds
What does degenerate mean
More than one codon codes for one single amino acid
