exam questions Flashcards
describe the primary structure of all proteins
- sequence of amino acids that form polypeptide
- joined by peptide bonds
describe one difference between the structure of DNA in a prokaryotic cell and in a eukaryotic cell
- circular not linear
- no introns
describe the mechanism of breathing that causes air to enter the lungs
- diaphragm flattens and contracts
- external intercostal muscles
- rib cage raises
- increase in volume of air in the thorax
- pressure decreases inside the lungs
explain why phospholipids can from a bilayer but triglycerides cannot
- have a hydrophobic tail that does not like water
- aq solution on either side
- triglyceride only have hydrophobic tails
describe how gas exchange occurs in single-celled organisms and explain why this method cannot used by large, multicellular organisms
- small organisms have a large surface area to volume ratio
- diffusion across the cell surface membrane
- diffusion pathway would be too long
explain how sucrose-transport proteins in leaf cells enable the production of a pressure gradient in the phloem
- sugars are pumped by active transport into the companion cells
- decrease in water potential
- water enters via osmosis
name the type of blood vessel that controls blood flow to muscles
arterioles
suggest how the shape of ATP synthase allows it to catalyse the synthesis of ATP
- active site complementary to ADP + Pi
- enzyme-substrate complexes form
suggest how the shape of ATP synthase allows it to allow the movement of H+ ions
- channel protein
- allows for facilitated diffusion
describe the behaviour of chromosome in prophase and metaphase of mitosis
- chromosomes condense and become visible
- chromosomes are pulled along the spindle apparatus to the equator of the cell
describe the hydrolysis reaction involved in the digestion of triglycerides
- breaking of ester bonds
- addition of water
