P1 - 2018 Flashcards
Name the blood vessels that carry blood to the heart muscle.
Coronary arteries
What is a monomer?
A monomer is a smaller repeating unit
Its a molecule from which larger molecules (polymers) are made
Other than both being disaccharides,
give one similarity and one difference between the structures of lactulose and lactose.
sim: Both contain galactose
+ both a glycosidic bond
dif: Lactulose contains fructose, whereas lactose contains glucose
faeces of people with constipation are dry + hard but can be treated by drinking lactulose which is soluble, but not digested or absorbed in the human intestine.
Use your knowledge of water potential to suggest why lactulose can be used to help
people suffering from constipation (2)
Lactulose lowers the water potential of faeces contents of the intestine
Water retained enters due to osmosis and softens the faeces
Give two features of DNA and explain how each one is important in the semi-conservative replication of DNA
(3)
Weak hydrogen bonds between bases allow two strands to separate
Two strands, so both can act as templates
Complementary base pairing allows accurate replication
what is the main biological molecule in a cell surface membrane?
phospholipids
what is the main biological molecule in a cell wall?
glycoprotein
Name the process by which prokaryotic cells divide
binary fission
Describe how you would test a liquid sample for the presence of lipid and how you
would recognise a positive result. (2)
Mix sample with ethanol, then water
positive result will be a White/milky emulsion
Name the taxon to which Drosophilidae belongs.
family
What is the proteome of a cell?
The proteome is the full range of number of different proteins that a cell is able to produce at a given time
Give two structural differences between a molecule of RNA (mRNA) and a molecule of transfer RNA (tRNA).
mRNA does not have hydrogen bonds, tRNA does
mRNA has more nucleotides
Starting with mRNA in the cytoplasm, describe how translation leads to the production of a polypeptide.
(5)
- mRNA associates with a ribosome
- Ribosome finds the start codon
- tRNA carries specific amino acid;
- Anticodon to codon
- Ribosome moves along to next codon
State and explain the property of water that can help to buffer changes in temperature (2)
water has a relatively high specific heat capacity
and can gain/lose a lot of heat without changing temperature
Water is used to hydrolyse ATP.
Name the two products of ATP hydrolysis.
Adenosine diphosphate
inorganic phosphate
