Topics to revise Flashcards
Signal transduction definition
cascade of events in which a message from outside of the cell enters the cell. (Usually second messenger molecules amplify response)
Types of bonds for tertiary and quaternary structures
hydrogen, covalent (disulfide bridges), ionic interactions, hydrophobic interactions
What are first messengers molecules as opposed to second messenger molecules
like the actual message - e.g. hormone
Mitochondrial pathway (5 steps)
- Damage
- Activation of proteins on surface of mitochondrial membrane
- Mitochondrial membrane ruptures
- Caspases are activated and they enter the nuclear pores and destroy DNA
- Dying cells display signals, destroyed by macrophages
Death receptor pathway (6 steps)
- Caspases are activated
- Cells shrink and develop blebs
- Caspases enter nuclear pores and destroy DNA and proteins
- Mitochondria break down
- Fragments bind to receptors on phagocytes and are destroyed
- Phagocytes release cytokines to prevent inflammation and neighbouring cell death
What happens to organelles in apoptosis
generally preserved
Important to remember about drawing a meiosis/mitosis diagram
Need to add like 2n = 4 e.t.c.
Steps of DNA replication
- DNA helicase separates the two strands, exposing the bases
- DNA is antiparallel and semi-conservative, so…
- On the leading strand, primer attaches, then complementary, free DNA nucleotides attach to form a continuous strand in 5’ to 3’ direction - catalysed by DNA polymerase
- On the lagging strand, the new DNA strand is made in pieces called Okazaki fragments, which are joined together by DNA ligase
Basic remember prompts for DNA replication (4 points)
- DNA helicase separates DNA,
- DNA is antiparallel and semi-conservative, so…
- On leading strand primer attaches, complementary free DNA nucleotides attach to form strand - catalysed by DNA polymerase
- On lagging strand, made in pieces 3’ to 5’ called Okazaki fragments that are joined by DNA ligase
Leading strand is what prime to what prime
3’ to 5’
Lagging strand is what prime
5’ to 3’
What enzymes are involved in DNA replication
DNA helicase, DNA polymerase, DNA ligase
Chiasma
Point of crossing over
Ratio of test cross with heterozygous
1:1:1:1
Offspring produced by linked genes that are different from parents name
Recombinant offspring
If you have to work out which letters go on top for linked genes,
do a cross
Steps for genetic engineering (5)
- Isolation of gene
- Insert gene into vector
- Transfer vector to organism
- Transformation of organism
- Selection of GMO
Southern blotting
separates DNA
Polymerase Chain Reaction Steps
- 94 degrees, to dentature
- 50 degrees and add primer, to hybridise two strands
- 72 degrees, DNA polymerase initiates DNA synthesis, free and complementary base nucleotides
Natural selection steps (5)
- Genetic variation exists in a population resulting in phenotypic variation within the population.
- In a changing environment, organisms with the favoured phenotype will have an improved chance of surviving and reproducing over those of less favourable phenotypes.
- Hence more offspring will posses the favoured characteristics
- And their frequency (and that of the alleles) within the population will increase across generations
- In time, evolution of a new species may occur.
Selective agents definition
Agents that ‘select’ for or against particular organisms surviving and producing offspring.
Darwin’s beliefs
different genotypes hence phenotypes, struggle for survival due to selective pressures, best suited will produce more, new variations can result in evolution
Adaptive radiation is what kind of evolution
divergent evolution
maybe read about it
Molecular clock definition
Uses fossil evidence and rates of molecular change to deduce the time in geological history when two species diverged.
DNA hybridisation steps
- DNA strands separated by heat
- Separated strands are mixed between species - more pairing = more similarity, less pairing = less similarity
- Molecule is reheated to separate strands
What is it called when you do radioactive chemical dating thing
Radiometric dating
What to know about electron spin resonance
older means more electrons spinning/energy rate
Difference between Hominoids, hominids and hominins,
Hominoids = all apes Hominids = great apes Hominins = bipedal
What homo has largest brain
homo neanderthalensis
Features to look for in skull
rounded jaw, more protruding jaw, larger brain, hip shape, arm length, brow bone prominence, vertical forehead, foramen magnum
What species is homo egaster
homo erectus
How long ago was homo erectus
1.8-500,000 yrs ago
When did homo sapiens evolve
150,000 yrs ago
Out of Africa theory
modern human evolved in Africa
Out of Africa theory evidence
fossils, mtDNA
Regional Continuity Hypothesis
evolved from homo erectus populations from around the world
How technological evolution developed due to cultural evolution
communication
Flanking regions
regions of DNA surrounding coding region. Two types are upstream and downstream.
Upstream region
contains promotor sequence, TATA box
Promotor sequence
tells where to start coding, TATA box
Downstream region
end transcription signal
Transcription steps (3)
- RNA polymerase attaches to promotor region, and unwinds DNA sequence (unpaired bases are exposed)
- RNA polymerase constructs mRNA by collecting free RNA nucleotides that are complementary to the DNA template strand to form pre-mRNA
- introns are spliced out, methyl cap is added to 5’ end and poly-A-tail to 3’ end
Translation steps
Need to learn see VCAA
Gene expression is
making polypeptide
Operon definition
functioning unit of genomic DNA containing a cluster of genes under the control of a promotor
In order to stop expression
repressor protein binds to operator sequence
Lac operon gene
B-galactosidase
Homeotic genes
regulator genes that play part in embryonic development
Allergic response process
- Upon first exposure to allergen, B cells develop into plasma cells that secrete IgE antibodies specific for the allergen.
- Some of these antibodies bind by their tails to a mast cell.
- Upon the second exposure, the allergen binds to IgE already on the mast cell, trig erring “degranulation” of the cell. Cellular granules release histamine and other inflammatory agents leading to the symptoms of the allergy.
Label for antibody
Antigen binding site
Light chains
Heavy chains
