target topic session

DNA sequencing

• quick

• Advantage bc we can use this to work out the new mutations and based on that we can work out the new antigens

• Once we know the antigens can develop new vaccines very quickly and efficiently

Bioinformatics

• molecular data ie DNA proteins

• Stored rapidly accessible way

• Used to develop vaccines in targeted way

Why is DNA described as being semi-conservative

• both strands of DNA act as templates and a new daughter strand is made

Why do scientists use bacteria

• replicate easily

• Grow anywhere no ethical issues

Why would nitrogen isotopes be used

• essential component of nitrogenous base

• Every time DNA rep takes place nitrogen has to be taken in from growth medium

Why is a curve s-shaped

• 1st oxygen causes a conformational change in the shape of Haemoglobin

• Allows more O2 to bind

• Cooperative binding

Haemoglobin stcrture

• quaternary

• 4 haem groups

• 4 polypeptide chains

• Each haem group had iron ion

Why would a more active species need to unload more o2

• for aerobic. Recap

Benefits of training at high altitudes

• low air pressure

• Low oxygen conc at high altitudes heart has to work harder to push blood around body becomes larger and increases stroke volume

• Lung capacity also increases to deal with low oxygen supply

• More RBCs will be produced to carry more oxygen around the body

• Bc the demand is high and supply in air is less

Describe structural features common to all viruses

• have capsid

• Linear DNA can have RNA as their genetic material

• Some have enzymes have reverse transcriptase

• Smaller than eukaryotes and prokaryotes

• No cellular features

Why does HIV have a protein capsid

• bind to receptors on host cell surface membrane

Purpose of envelop of HIV

• lipid bilayer

• Consists of lipids and proteins from cell membrane of host cell

• Helps HIV avoid detection by hosts immune system

Lytic cycle phases

Attaches to cell membrane of host cell using attachment proteins

Infects host cell by injecting its DNA

Host cell proteins and enzymes

To produce new virus particles

And are assembled

Undergoes lysisn

Why can liposomes pass through cell surface membrane

• phospholipid bilayer

• Lipid can dissolve and pass through

Why are viruses always suitable vectors for gene therapy

Describe how replica playing is carried out

What’s the stcrture of enzyme

• active site

What enzyme causes the DNA of virus to combine with host

Intergrase

Why could common cold not infect cells if they enter the blood through a cut in skin

• Virus attaches onto specific receptors

• Receptors there are no receptors on RBCs

What type of cell can HIV enter the immune system

• macrophage

Why does not all contaminated food = food poisoning

• stomach acid kill bacteria

• Competition with gut flora

• Level of O2

Why would an alcohol based hand-wash not killer virus

• virus not surprised by envelope

• Alcohol does not damage the protein coat

• Protein is hydrophilic

Suggest why viruses are not always suitable vectors for gene therapy that needs to be repeated at intervals

• virus is used as a vector = immune r in recip

• Virus is injected again

• Memory cells make antibodies that agglutinate the virus particle together

• Prevent from entering the cell

Describe replica plating

• press a piece of sterile velvet onto colonies on first agar plate

• Keep orientation of velvet the same + then press it onto another sterile agar plate

• So some bacteria from each colony on first plate are placed onto the second plate in same location

• Replace lid + incubate plate for 24-48 hours at around 30 to 35 degrees

What does tetracycline affect

• ribosome

Describe the mammalian structure of the heart

• walls of all chambers are composed of cardiac muscle

• walls of ventricles and thicker of those of atria

• AV valves separate atria from ventricles

• Semi lunar are at entrance to the arteries leaving the heart

• Tendons found between walls of ventricles and flaps of AV valves

• Aorta leaves from left ventricle and pulmonary artery from right ventricle

• Vena cava and pulmonary vein enter the atria

• Heart supplied with coronary arteries

• Pacemaker is found in right atrium and AV node between atria and ventricles

• Purkyne fibres radiate from apex of heart

State the function of the valves in circulatory system

• found in veins in pulmonary artery the aorta and between atria and ventricles

Explain why valves are found where they are in circulatory system

• Present in veins bc there is not a continous high pressure pushing blood forward by body muscles and would fall back when these relaxed again

• Found in pulmonary artery + aorta stop blood flowing back to ventricles when they relax relax after pushing blood out of heart

• Found between atria + ventricles bc blood would move back up to atria when powerful ventricle muscles contracted when pushing

What is happening at QRS and T phases of the ECG

• during QRS ventricles are depolarising during the T they are depolarising

Describe the sequence of events in clotting process

• blood vessel is daMagee

• Cell fragments called platelets stick to wall of damaged blood vessel form a plug

• Fibrin are strands that form a mesh traps RBCs + platelets to form clot

Describe how atherosclerosis develops

• endothelial cells damaged due to inflammation

• WBCs accumulate at damaged area

• Build up of cholesterol + fibrous tissue plaque forms

• = increases likelihood of clot forming

Explain how atherosclerosis can causes chest pain associated with an attack

• reduced blood flow to cardiac muscle through coronary artery

• Heart receives less oxygen respires anaerobically

• By - product of anaerobic resp is lactic acid builds up = pain

Why is a double circulatory system needed by mammals but not fish

• mammals need more O2 than fish bc they have to move around without support of water and maintain a constant body temp

• Takes lot of energy cells need lots of glucose of oxygen produce lots of waste

• Double c - one part carries oxygenated blood from heart to body and the other carries deoxgenated blood from heart to lungs to be oxygenated blood from heart to lungs carried oxygenated back to heart

• Blood delivered to body at high p

• Blood is going through tiny blood vessels i lungs low pressure gas e takes place

• Oxygenated blood went to big vessels it would be very slow

• Returns to heart oxygenated blood can be pumped hard + sent around body at high p

What’s role of phagocytes

• consist of monocytes which later settle to for, macrophages and neutrophils

What do neutrophils look like

• lobed nucleus

Why would a patient have a high number of eosinophils

• bone marrow stem cells must have produced more of them

• Parasitic infection can also cause more of these cells to be released

When asked to analyse the data of evolutionary relationships

• It’s important to say closely related instead of similar

• Or if not similar distantly related

What do most closely related animals have

• more similar DNA

What is staphylococcus and salmonella

• Staphylococcus release exotoxins

• Salmonella release endotoxins

Why would gender mean women are at less risk of heart disease

• gender bc of presence of oestrogen in women

• More men than women smoke

Why would age affect heart disease

• more time to develop atherosclerosis

• Less active lifestyle

• High bp

• Less elastic arteries

Compare IPS and embryonic stem cells

• both have potential to divide indefinitely

• Both have potential to differentiate into number of cell types

Differences between embryonic stem cells and IPS cells

• IPs were taken from adult cells and embryonic stem cells taken from morula

• IPs have named gene like Oct4, sox2 added by embryonic do not

• There are no ethical issues surrounding the use of IPS cells

• IPS cells form adult cells whereas embryonic cells form younger cells

• IPS cells will produce patient-matched cells but embryonic stem cells will be antigenic

Why would you choose a specific temp?

• lower temp less KE

• Higher Denaturation

Role of mitochondria

• respiration and oxidative phosphorus

• Contain electron transport proteins

Steps for stats tests

• establish null hypothesis

• Decide on stats test

• Do calculations look at critical value in data table at 0.05 p value

• Draw conclusion based on which value is bigger

Name molecule that contains calcium ions in cell walls of a plant

• Calcium pectate

What’s happens to movement of ions in aerobic r

• aerobic r - more oxygen

• Ions move done conc gradient

What’s a tissue?

A group of similar cells working together to carrry out a particular function

What do ethanol and lactate do?

• they both regenerate NAD

• Allow glycolysis to continue

Does mRNA have hydrogen bonds

No

What’s role of ligase in DNA replication

• forms bonds between phosphate and deoxyribose

What mutations lead to a frameshift

• insertion and deletion

What can a substitution mutation do

• either cchang AA seq or not

• And have effect on strture or not

What bonds does DNA polymerase form

• phosphodiester bonds

What happens to leading strand during DNA replication

• synthesised continuously

What happens to lagging strand during DNA replication

• requires DNA ligase to join fragments on lagging strand

Describe strture of a DNA molecule

• composed of nucleotides held together by phosphodiester binds

• Complementary base pairing held together by H-binds

• 2 sugar phosphate ebackbk d = double helix

Describe the role of ribosomes in protein synthesis

• hold tRNA on mRNA

• for translation.

What do secretory vesicles do

Transports proteins to cell surface membrane

Why is replication of DNA produces aseptic conditions

• mRNA synthesis is prevented

Collagen stcrture

• 3 polypeptide chains

• H-bonds form

• Triple helix

Fibrous protein

• little to no tertiary stcrture

• Insoluble in water

• Long polypeptide chains

3D tertiary strture of a protein

3D folding of a protein held together by bonds bet R groups

Why does water flow into part of cell where soluble parts are locate

• enters by osmosis

• High water p to low water p

Describe the events that take place when T helper cell activation following the formation of pseudopodia by macrophage

• macrohphaxe engulf pathogens and digest

• Antigen attaches to MHC and macrophage becomes APC

• CD4 antigen on T helper binds to macrophage

Describe what is meant by the secondary strcuture of a protein

• folding of protein due to formation of H-binds

Why can a misfolded protein not be digested by protease enzymes

• not fit active site of protein

• Enzyme unadulterated to hydrolyse the peptide bind

• Protease enzymes have an active site specific to amino acid

How does primary stcrture of a peptide hormone determine its properties

• R groups determine position of bind

• Hydrophilic R groups need to be on outside of hormone so it can dissolve in blood

Why is protein soluble in water

• hydrophilic r groups on outside

• Hydrophobic on inside

• Exposed R groups can form H-bonds with water

Signifcjae of respecting seqs of AAs in formation of protein

• fibres close together

• Form binds

• Hold polypeptide chains together

What does it mean if molecule form 1,6 glycolic bond

• the bond is between C1 and C6

What molecule is produced in condensation reaction

Water

Why is the photon of light needed for carbon fixation an underestimate

• not all wavelengths of light can be absorbed

• C atoms in cell is underestimate

• Not all ATP generated in LDR is used in calvin cycle

Why would nuclear DNA be inherited from the mother and father but only mitochondrial DNA inherited from mother

• both gametes have nuclei that fuse together in fertilisation

• But the egg only have mitochondria

How could a mutation affect an enzyme

Mention active site and function of enzyme

What is ATP synthase

Channel protein

How can a mutation result in shortened protein

• mutation may result in stop codon being created

• Translation ends a lot sooner

What produces lactate

• pyruvate and reduced NAD

How are sugars transported in pholem

• mass flow

• Sugars move out of pholem into sink

• Water enters pholem

• Sugars move from a region of low hydrostatic p in pholem

Why is there a time delay between infection and symptoms appearing

• time for large no. Of cells to be damaged by viruses to cause symptoms

Why antibiotics not taken by pol with viral infections

• antibiotic r is a selection p

What type of immunity is injection of antibodies

Artificial passive

When there is error bars

Always comment on

Explain importance of thylakoid membranes in light d stage

• photosystems so light is absorbed

• Photolsyis of water to give water and electrons

• ATP synthase so H+ can pass through

• Membrane enclose so H+ can accumulate

• ETC so reduced NADPH produced

• Redox reactions

Why is it necessary to keep thylakoids and enzymes together

• keep thylakoids and enzymes together

• Enzymes need to be in solution to function

Why can water be transported across the membrane

Even tho it’s polar it’s very small

How is the structure of membrane controls transport of polar molecules

• phosphate head is on outside

• Fatty acid tails inside

• Polar molecules are hydrophilic

• Large, charged molecules cannot pass throigh fatty acid tails

Compare and contrasts effects on smth and given and graph

Refer to specific data from graphb

• what does a non-competitive inhibitor do

• changes active site

Role of mitochondria in rod cells

• make ATP

• For ion pump

Describe how light causes a change in release of glutamate from rod cells

• rhodopsin involved

• Retinal changes from cis to trans

• Na+ stops diffusing in rod celol

• Inside of cell is hyperpolaised

• Stops glutamate release

Why is an electron microscope used rather than a light microscope

• wavelength of electrons is shorter

What steps did I forget in control of heartbeat

• SAN acts as pacemaker

• Delay at AVN

What does introducing a small number of individuals in population do

• Founder effect

Principles of ex-situ

• Use of zoos to protect endangered species

• Education about conservation awareness

Issues associated with ex-situ conservation

• avoid inbreeding use of stud books

• Ethical issues

• Loss of normal behaviour

What affects molecules pass through in ultrafiltration

• size of pores in basement membrane

• how does daylight and light affect NPP

• increases it

• More Photosythesis greater than resp

• Light is limiting f

• NPP decreases and resp rate increases more than Photosythesis rate