essay topics and links Flashcards
(24 cards)
STARCH
- polysaccharide of glucose
-1,4 and 1,6 glycosidic bonds
- amylose and amylopectin
- branched, coiled, compact, insoluble
GLYCOLYSIS
- glucose phosphorylated to glucose phosphate
-glucose phosphate to triose phosphate
- triose phosphate to pyruvate for link reaction
- net 2 ATP and reduced NAD
LIGHT DEPENDANT REACTION
- photoionisation- chlorophyll absorbs electrons
- electrons excited, enter ETC, REDOX reactions, energy
- H+ pumped from stroma to thylakoid space- conc grad ]
- Photolysis of water
- H+ into stroma via ATP synthase by FD
- ATP and reduced NADP made
LIGHT INDEPENDANT REACTION
- RuBP and CO2 catalysed by rubisco, makes Glycerate phosphate
- GP reduced to triose phosophate using ATP and reduced NADP
- after 6 spins makes hexose sugar e.g glucose for respiration
- regenerates RuBP
ACTION POTENTIAL
- resting potential -70mV. Na/K pump 3 Na out 2 K in, negative inside.
- Stimulus opens Na channels. Na+ in neurone. Threshold of -55mV met, VGC sodium ion channels open. Influx of Na+ depolarisation to +40mV.
- Na VGCs close, K+ VGCS open. K+ out- hyperpolarisation of neurone so K VGCs close. Repolarisation.
- resting potential again- AP forms after refractory period.
CONTROL HEART RATE
- increase CO2 concentration- chemoreceptors detect
- more impulses to medulla along sympathetic NS
- more impulses to SAN, heart rate increases, acidity decreases
WATER
- metabolite in condensation reactions
- solvent for metabolic reactions
- high SHC- buffers changes in temperature
- high LHV- cooling effect via evaporation
- adhesion- hydrogen bonds to walls
- cohesion- hydryogen bonds with other water molecules
COHESION-TENSION
- transpiration- water evaporates
- lowers WP of leaf cells, more water drawn up xylem. negative pressure- tension
- cohesion- H bonds- continous column
- adhesion- stick to xylem walls
- photosynthesis, growth, cooling
PROTEIN SYNTHESIS
- DNA helicase breaks H bonds
- RNA nucleotides align by complementary base pairing
- G to C, C to G, U to A, T to A
- RNA polymerase forms phosphodiester bonds- forms mRNA
- splicing to form mature mRNA
- mRNA binds to ribosome, mRNA codon and tRNA anticodon complementary, tRNA brings specific AA
- peptide bond forms- condensation reaction using ATP
HAEMOGLOBIN
- quarternary- 4 polypeprtide chains a-globin and B-globin
- haem group containing Fe2+
- Fe2+ binds to oxygen
- high affinity at lungs to load oxygen, low affinity at tissues to unload oxygen
OSMOREGULATION
- collecting ducts in nephron for water reabsorption
- osmoreceptors in hypothalamus detect low blood WP,
- increase of ADH into blood from PG, ADH binds to receptors lining collecting ducts.
- vesicles with aquaporins fuse with cell membrane and increase permeability, water reabsorbed into blood
HOMEOSTASIS
- osmoregulation prevents cells become hypotonic (low WP, water in, swells) or hypertonic (high WP, water out, shrinks)
- allows normal cell activity and metabolic reactions to occur
ABSORPTION
- Na+ out of epithelial cell into blood by active transport through Na/K pump. Lowers concentration of Na+ in epithelium. Conc gradient.
- Na+ in by FD through co transporter protein with glucose.
- Glucose actively transported low to high conc.
- High glucose in epithelial cell, low in blood. Glucose by FD into blood
GLYCOLYSIS
- glucose phosphorylated by 2 ATP into glucose phosphate, into TP,
- TP oxididsed to pyruvate.
- 4 ATP made and 2 used so 2 net ATP made for active transport and muscle contraction.
MEMBRANES
- fluid mosaic model, phospholipid bilayer, hydrophobic vs hydrophilic, channel proteins and carrier proteins, glycoproteins and glycolipids for cell recognition, cholesterol(restricts movement of molecules maintain membrane stability)
- receptor proteins, specific binding site shape, complementary to antigens
IMMUNITY
- T cells have receptors which respond to antigen presenting cells, they bind, divide by mitosis and form clones, can also stimulate B cells to divide and produce antibodies
- B cells have specific receptors complementary to antigens
- important to eliminate pathogens and protect immune system
HAEMOGLOBIN
- quaternary protein, 4 polypeptide chains a-globin and B-globin, - 4 prosthetic haem groups, each contain Fe2+ oppositely charged to O2- so bind.
- Positive co-operativity- 2nd and 3rd binding easier.
- Hb has high affinity at lungs at low pO2 so loads oxygen readily, low affinity at respiring tissues, unloads easily.
OXIDATIVE PHOSPHORYLATION
- oxygen in respiration as terminal electron acceptor.
- Electrons down ETC, makes ATP.
- Without terminal electron acceptor, ETC stops, no ATP for active transport, muscle contraction.
- Anaerobic respiration.
importance of ions
digestion -> glycolysis
LDR -> LIR
action potential -> control heart rate
HB -> oxidative phosphorylation
importance of bonds
starch -> glycolysis (glycosidic)
water -> cohesion-tension theory (hydrogen)
protein synthesis -> Hb (peptide)
lipids -> osmoregulation (ester)
importance of interactions between cells and environment
nitrogen cycle -> nitrates for proteins
succession -> biodiversity
selection ->
taxis,kinesis, reflex arc -> generating action potential
importance of water
water -> cohesion tension theory
osmoregulation -> homeostasis
LDR -> LIR
tissue fluid -> ?
importance of membranes
osmoregulation -> homeostasis
membrane structure -> immunity
absorption -> glycolysis
transport mechanisms -> LDR to make ATP
importance of diffusion
importance of nitrogen containing compounds
importance of shape
importance of ATP
importance of enzymes
LDR -> LIR (ATP synthase)
protein synthesis -> HB (DNA helicase and RNA polymerase)
digestion -> glycolysis (maltase, amylase, peptidase)
oxidative phsophorylation -> ATP for active transport ?
causes/importance of genetic diversity
meiosis -> selection
biodiversity ->
evolution and genetic drift -> speciation
selection -> adapt to changing environments
importance of proteins
importance of control of movement in cells and organisms
importance of DNA as an information-carrying molecule and its use in gene technologies.
importance of cycles in biology
