Finals 1 Flashcards
describe True-bred
True-bred or purebred generations are that which have only one genetic allele type.
A combination of two for a second generation would be a hybrid. The second generation will only show dominant phenotype.
Describe allele
An allele is an alternate form for a gene, where there is a change in the DNA sequence. One gene may have many alleles being heterozygous, that the alleles are different. only one allele is expressed as the phenotype.
Describe Segregation during meiosis
formation of gametes is during meiosis, two alleles for a heritable character segregate during gamete formation.
Describe Difference between X linked and autosomal mode of inheritance
X-linked recessive will be prominent in men.
Autosomal will be equally shared
Describe Mendel’s model
Each character has 2 copies of a gene from each parent. Allels at a locus may differ and thus the dominant one will take possession.
Law of segregation - two alleles for a heritable character segregate during gamete formation.
Law of independant assortment - each pair of allels segregates independantly during gamete formation in metaphase 2.
Describe Law of independent assortment
2 or more genes assort independently
Each pair of alleles segregates independently of any other pair of alleles during gamete formation
Describe Incomplete dominance
combination of alleles results in a phenotype that is not existent from pure-bred species.
Describe X inactivation
Occurs in female mammals where one X chromsome is inactivated in each cell during early development foring Barr bodies, most genes here are not expressed.
state Respiration stages
Glycolysis
Citric acid cycle
Oxidative phosphorylation
Describe When and what molecules enter glycolysis and citric acid cycle
Proteins can enter into glycolysis as pyruvate, or citric acid cycle as acetyl CoA
Glycerol enters into glycolysis as glyceraldehyde
Fatty acids enter into citric acid cycle as Acetyl coA
Cross between AaBbCc and AaBBCC, what is probability of AaBbCC offspring.
(multiply punnet square probabilities for each letter’s probability)
½ x ½ x ½ = ⅛
Describe alleles, genotypes and phenotypes of blood type
Alleles - I^A, I^B, i
Genotypes - 6 combinations of 2 alleles
Phenotypes - A, B, AB, O
Describe Adenosine triphosphate
adenine group attached to Ribose sugar attached to three triphosphate groups.
ATP is hydrolysed to ADP releasing energy held in the phosphate bond.
Describe conditions for spontaneous reaction
Only exergonic reactions that release energy occur spontaneously, however endergonic and exergonic reactions can be coupled so the overall reaction is spontaneous (delta G). Which takes in account enthalpy and entropy.
Describe free energy in terms of delta G
More free energy relates to +G, less stable. As free energy decreases (DeltaG < 0) released energy is used to do work. This increases disorder. Exergonic = -DeltaG
compare phenotype ratio and genotypic ratio
Phenotypic ratio is the ratio of outcomes that occur, only including final expressed phenotype produced from allele combinations.
Genotypic ratio is the ratio of allele combinations, expressed in a punnet square. commonly (1, 2, 1)
Describe Allosteric regulation
where a proteins function at one site is affected by binding of regulatory molecules at other sites.
Express delta G
Delta G = Delta H - T Delta S
Enthalpy = H
Entropy = S
Describe Citric acid cycle
Within the mitochondria, Acetyl CoA (2C) joins with oxaloacetate(4C) 8 steps with enzyme catalysis 2 CO2 released 3 NADH formed from NAD 1 FADH2 formed from FAD 1 ATP produced
(x2 for total released per glucose)
Describe chemical intermediates from glycolysis / TCA cycle
They can be used as building blocks for anabolic processes in the cell
Describe Chemiosmosis
process where ATP is produced in ETC and photosynthesis. Electrons move through a gradient producing H+ gradient across membrane driving ATP synthesis via ATP synthase complex.
Describe pyruvate role in catabolism
Pyruvate exists as a key junction in catabolism, it may continue as acetyl CoA or become ethanol / lactate depending on O2 presence.
Describe OILRIG
Oxidation has a substance lose an electron
Reduction has substance gain an electron
Describe Breakdown of nitrogenous molecules:
Proteins / nucleic acids -> amino acids/nitrogen bases -> NH2 amino groups -> ammonia/urea/uric acid
Describe Excretory organs:
Epithelial solute pump (chloride pump in bony fish gill)
Internal tubular excretory organs, form / modify / expel liquid urine (vertebrate kidney)
Describe effect of ADH
increases reabsorption thus reducing blood osmolarity
ADH binds to receptor, triggers protein kinase A, sends vessicles with aquapourins to fuse with membrane of collecting duct cell.
Describe Phagocytic cells:
Macrophage - large debris, from spleen and tissue
Neutrophils - blood
Dendritic cells - tissue and skin
Eosinophils - epithelial tissue, attack multicellular bodies
Describe Innate immune response
immediate response to lesion. Mast cell / macrophage give signaling molecules. Neutrophil response, with macrophage eliminate antigens.
Describe cyclic electron flow
Electrons are energised through pigments in photosystem 1 to primary electron acceptor, then to Fd, then Cyt c, the Pc, then back into photosystem 1. Producing ATP without NADPH. (calvin cycle requires more ATP than NADPH)
Describe calvin cycle
Carbon fixation - CO2 is added to 5 C RuBP through rubisco.
Reduction - G3P sugar produced from 6 ATP / 6 NADPH leaving 6 ADP / 6 NADP+ / 6 Pi
Regeneration of RuBP - through 6 ATP leaving ADP
Describe Photorespiration
O2 added to RuBP, forms glycolate (2C) useless compound and CO2 while also consuming ATP. other compounds produced are the same as those produced in calvin cycle.
Describe photosystems
Structures in thylakoid membranes made of pigments, organic molecules and proteins forming light harvesting complexes and a reaction center where energy transfers excited electrons from chlorophyll (a) to primary electron acceptors (first step of the light reactions).
Photosystem 1 / photosystem 2 form part of photosynthetic electron transport chain.
Describe Adaptations to reduce photorespiration in arid environments
CAM plants close stomata during day and open them at night.
Mesophyll cells fix CO2 into 4 C organic acids during night, stored in vacuole. Light reactions of photosynthesis supply ATP and NADPH, CO2 is released from organic acids and incorperated into sugar by calvin cycle.
Describe Adaptations to reduce photorespiration in arid environments
CAM plants close stomata during day and open them at night.
Mesophyll cells fix CO2 into 4 C organic acids during night, stored in vacuole. Light reactions of photosynthesis supply ATP and NADPH, CO2 is released from organic acids and incorperated into sugar by calvin cycle.
Describe the tissues of animals and their purpose
Epithelial - internal / external cover
Connective - structureal and support
Muscular - movement
Nervous - infomation
Describe levels of control in organism physiology
Transcriptional control - gene activation / inhibition
Post transcriptional control - splicing
Activity of synthesised proteins - allosteric (enzyme inhibition) regulation of metabolic pathway
Describe osmolarity and its control against external environment
Osmolarity = total concentration of osmotically active solutes
Osmoconformer : internal osmotic conc = external
Osmoregulator : internal osmotic conc =/ external
Describe kidney’s role in regulation
Kidneys provide ionoregulation / osmoregulation through nephron which filters, reabsorbs and secretes.
Renal medulla is responsible for osmoconcentration
Describe osmolarity of the nephron:
Ascending loop impermeable to water, actively passes Cl-, passively passes Na+ balancing charge
Descending loop permeable to water, releasing it.
Countercurrent exchange between loops generates osmotic gradient in renal medulla, water may leave collecting duct (through ADH) due to this gradient.
Describe convection and ventilation’s purpose in O2 diffusion
Convection is the bulk movement of a medium and is generated in animals through ventilation, this increases diffusion of oxygen.
Describe CO2 transport in blood
Most CO2 is transported as bicarbonate ions HCO3 (hydrated from carbonic acid H2CO3) though some CO2 binds to heamoglobin.
Describe Adaptive immune system:
Humonal immune response - antigen exposure stimulates B cell to produce plasma cells, for antibody production, and Memory B cells
Cell mediated immune response - Antigen presenting cell stimulates Cytotoxic T cell, producing Active cyto T cell and memory T cell.
Neutral response - antigen presenting cell stimulates helper T cell which stimulates Cyto T cell / B cell, also forms memory helper T cells which stimulate memory B cells / memory cyto T cells
Describe B cell structure and function
cell has antigen receptor with, 2 binding sites at end with variable regions coming from constant regions coming from transmembrane region coming from heavy chain.
Once bound to antigen, B cell forms antibody producing cells, which bind to antigen, and also memory cells to respond to future antigens forming MHC complex with antigen.
Describe T cell structure and function
cell has antigen receptor with, binding site broken into 2 chains (alpha, beta) at end of variable regions coming from constant regions coming from transmembrane region.
Receptor binds to antigen expressed by MHC.
Helper cell will respond by producing clones while releasing cytokines to activate B cells and cytotoxic T cells which binds to antigen fragment on infected cell and kills it.
Describe
G protein linked receptors
G protein contains GDP which attaches to G protein linked receptor which has bonded to signal molecule. G protein swaps GTP for GDP, then binds to enzyme on membrane (losing Pi), activating enzyme to function.
Possible outcome involves enzyme using ATP to activate cAMP proceeding to activate protein kinase.
Describe Tyrosine kindase receptors
signal molecules bind to sites, Alpha helix in membrane form dimer, tyrosine kinase regions activate, dimer phosphorylates at the expense of 6 ATP, binding Pi to tyr molecules. Relay proteins are activated by phosphorylated dimer.
Describe Ligand gated ion channel receptors
Ligand gated ion channel opens / closes in response to signal, (change in ion concentration / signal molecule)
Synapses between nerve cells
Describe Signal transduction pathway
Reception may result in several metabolic effects. May involve several steps commonly protein phosphorylation(cascade of protein kinease) allows for amplification of signal.
Describe Hormones and growth factors rate of effect
Can have rapid or slow effect,
Rapid - Glucagon / adrenalin (response to blood glucose and stress)
Slow - growth factors, cascading changes, gene alterations. (receptions, transduction, response)
Describe Glucose homeostasis -
Low glucose, alpha cells of pancreas stimulated to release glucagon, liver breaks down glucagon into glucose, blood glucose rises.
High glucose, beta cells of pancreas stimulated to release insulin, body cells take up glucose, liver forms glycogen as well, blood glucose decreases.
Describe Phosphorylation cascade
Tends to involve G protein receptor and protein kinase. Inactive kinase is activated by relay (cyclic AMP), with ATP, activated kinase 1 activates kinase 2, 2 then activates 3 with ATP, 2 returns to inactive with release of Pi. this continues until protein is activated like kinase.
Describe Cell signaling specificity
Signal molecule tends to be specific for binding enzyme, resultant response may involve a long pathway, or inhibition of other pathways or several responses.
Describe Types of cell signalling:
Local signalling - Gap junctions, plasmodesmata (plants)
Local signalling - direct contact of membrane proteins, local regulators like neurons (remote)
Distant signalling - hormones (remote)
Describe remote cell signalling
Signal reception - G protein linked / tyrosine kinase / ion channel
Signal transduction pathway - relay pathway
Cellular response
Describe Caffeine
Part of xanthine group like adenosine, which normally is neurotransmitter, caffeine inhibits adenosine at synapse.
Describe Synapse
Voltage-gated calcium channel at end of pre-synaptic neuron open when AP reaches synapse, letting Ca into cell. Ions make synaptic vessicles fuse with membrane releasing neurotransmitter which diffuse accros synaptic cleft to bind with neuroreceptors in post synaptic mebrane, openign channels allowing ions to enter, results in depolarisation of post synaptic cell membrane, initating AP.
Describe Cytoplasmic response
reception of (epinephrine) to G protein results in transuction cascade activating a lot of stuff within the cell resulting in a large portion of glucose-1-phosphate release.
Describe mating in yeast
Mating factors are exchanged between cells which bind to receptors, resulting in cell fusion, new cell includes all genes from both cells.
Describe Acetylcholine
Neurotransmitter used at synapses. Removed from synapse by acetylcholinesterase.
Describe Cocaine effects
Blocks dopamine transporters from reabsorbing dope in synapse, allowing dope to bind continuously to dopamine receptors.
Describe epigenetics
Study of heritable changes in gene activity that occur in absence of DNA sequence changes
Can be due to methylation
