Biology unit 5

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  • Created by: Sopha8
  • Created on: 15-06-15 19:24
How does insulin lower blood glucose level?
released from beta cells in pancreas-bind to liver cells-increase permeability-glucose moves into cell by facilitated diffusion-down concentration gradient & activate enzymes-stimulate glycogenesis-glycogen stored in cytoplasm of liver & muscle cells
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What are the 5 enzymes involved in genetic processes? what is their functions?
1-reverse transcriptase cDNA for mRNA 2-RNA polymerase mRNA from DNA 3-DNA polymerase hybridise free nucleotides 4-restriction endonuclease cut at sequence 5-DNA ligase joins sticky ends
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How do you convert for um to mm? what is the equation for working out magnification?
um/1000 =mm magnification=length of image/length of specimen
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What is the function of a lysosome?
contains digestive enzymes that can digest invading cells or break down worn out components of cell
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Describe the second messenger model for adrenaline
binds to liver cell-activates adenylate cyclase which converts ATP to cyclic AMP-this is the secondary messenger which stimulates cascade of events causing glycogenolysis
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What is a codon?
base triplet on mRNA
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What base on RNA is different to DNA? What is its complimentary base pair?
Uracil which is complimentary to adenine
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Draw a graph showing the stages of an action potential
:
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How do you find the diameter of a sample using a microscope?
use a graticule that has been calibrated against something of a known size
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Describe the factors that decrease genetic diversity
1-genetic bottleneck- event cause reduction in population so less alleles in gene pool 2-founder effect-new colony less alleles that original 3-selective breeding
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How does cholera cause dehydration?
toxin opens chloride ion channels in epithelial membranes so Cl- ions move into small intestine lowering water potential. water moves out of blood into lumen causing diarrhoea
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Explain how waters moves into a plant from the soil
active transport of ions like nitrates lower water potential in root hairs so water drawn in from soil. from the root hair cells, water moves down concentration gradient toward the xylem takes one of 2 paths - apoplast and symplast
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What is the structure of haemoglobin?
4 polypeptide chains each with a haem group that has an Fe2+ ion which can reversibly bind to O2
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How can DNA hybridisation be used for classification?
Mix single strands of DNA from 2 different species, complimentary base pairs will hybridise together then heat mixture, the higher the melting point the more complimentary bases so more similar to each other
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What is the Bohr effect?
:
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What are 3 diseases of the lungs? briefly describe them
fibrosis-scar tissue increase diffusion pathways, reduce volume of air each breath. Emphysema-foreign particles in alveoli phagocytes to area- produce enzyme that breaks down elastin so cant recoil to expel air, damage wall reduce SA for diffusion
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Card 2

Front

What are the 5 enzymes involved in genetic processes? what is their functions?

Back

1-reverse transcriptase cDNA for mRNA 2-RNA polymerase mRNA from DNA 3-DNA polymerase hybridise free nucleotides 4-restriction endonuclease cut at sequence 5-DNA ligase joins sticky ends

Card 3

Front

How do you convert for um to mm? what is the equation for working out magnification?

Back

Preview of the front of card 3

Card 4

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What is the function of a lysosome?

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Card 5

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Describe the second messenger model for adrenaline

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