As Biology Flashcards
SER
RER
- Makes lipids/steroid
- Makes/transports protein
Golgi apparatus
Stack of flattened sacks (cisternae)
Modifies+packages protein into vesicles
Makes lysosomes/glycoproteins/gylocolipids
Lysosome
Hydrolytic enzymes
Breakdown unwanted substances
Centriole
Centrosome
Microtubule
Made of 9 triplets of microtubules
Organises spindle fibre during cell division
Made of a-tubulin+b-tubulin-form dimers-joined into 13 protofilaments (supports cell. Spindle separates chromatids. Involved in beating movement of cilia/flagella)
Microvilli
Cilia
Cell membrane projections that increase surfae area for absorption
Hair like projections made of microtubules. Allows movement of substances across cell surface (mantains flow of mucus to remove debris)
Has 2 central microtubules+ring of 9 microtubules doublets made of A+B microtubule. A microtubules have inner and outer arms made of dynein.
Lock and key hypothesis
Active site+substrate fit exactly and are complementary
Induced fit hypothesis
Not exactly complementary and not exact fit. Changes shape slightly.
Inmobilised enzymes
No enzymes in product
More tolerant to changes in temperature and pH
Reused
Denature
Bonds break
Tertiary structure changes
No longer complementary
Cannot bind
Cell signalling
Stimulis Ligand is secreted Binds to receptor Transduction Signalling cascade-G protein,second messenger Enzymes Signal amplification
Mitosis uses
Asexual reproduction
Repair of tissue
Replacement of cells
Growth of multicellular organisms
Base pairing
A=T/U
C=_G
Purines(A/G)=2 rings
Pyrimidines(C/T/U)=1 ring
Antibiotic
Substance that comes from living organism capable of killing/inhibitibg the growth of a microorganism
Genetic code
Triplet code
Universal
Punctuations
Degenerated
Source
Sink
Green leaves/Storage organs/food stores in seeds
Roots/Fruit
Phagocytosis
Pathogen invades
Cells release chemicals (histamine)
Attracts neutrophils (chemotaxis)
Receptors in neutrophils bind to antibody in pathogen
Endocytosis (neutrophil cell surface membrane engulfs pahogen+traps it in phagocytic vacuole.
Lysosomes kill+gigest
Antibody
Glycoprotein made by specialised lymphocytes in responce to the presence of a specific antigen
Each antibody has a shape complementary to its specific antigen
Antigen
Substance that is foreign to the body and stimulates an immune response
Endocytosis
Exocytosis
Bulk movement of liquids/solids into a cell by the infolding of the cell surface membrane to from vesiles (ATP)
Bulk movement of liquids/solids out of a cell by fusing of vesicles with cell surface membrane (ATP)
Rate at which substances diffuse
Temperature
sa:volume
nature of molecules
steepness of concentration gradient
Bohr shift
CO2+H2O= H2CO3 (carbonic acid) using carbonic anhydrase
H2CO3 dissociates-H+HCO3-(Hydrogen carbonate ions)
H+makes blood more acidic (lower pH)
Haemoglobin combines with H+ to form HHb(heamoglobinic acid)
Affinity is reduced
O2 is released
Chloride shift
Hydrogen carbonate ions diffuse out of red blood cell into plasma
To balance this, Cl- move into red blood cell
This prevents cell from becoming too +
Enzyme definition
Globular protein that acts as a biological catalyst
V max
The maximum rate of an enzyme controlled reaction in which all active sites are occupied
Km
Substrate concentration at half v max. Higher Km=lower affinity (strength of attraction)
Plasmolysis
Water diffuses out of cell. Protoplast separates from cell wall
Macromolecule
Large molecule:
polysaccharides
proteins
nucleic acids
Monomer
Polymer
- Simple molecule used as basic building blocks for synthesis of a plolymer. Joins by covalent bonding: monosaccharide/amino acids/nuclotides
- polymer: macromolecule
