finishing touches <3333 Flashcards
what is cell metabolism
the total set of reactions in a cell
do enzymes lower or raise the activation energy for a reaction
lower
what happens in a reaction as you increase substrate concentration
the rate of reaction increases but then becomes constant
what is respiration
the breakdown of respiratory substrates to release energy
what does the phosphorylation in the energy-investment phase of glycolysis result in
the generation of more ATP in the energy pay-off phase
what are examples of cellular processes that require energy
protein synthesis, contraction of muscle, active transport, DNA replicationn and carbon fixation
how do regulators control their internal environment
metabolism eg water balance, temperature, blood sugar
what is homeostasis
the ability of the body to maintain a stable internal environment despite changes in external conditions
how does negative feedback control return temperature to normal
it uses corrective responses to reverse changes in internal temperature
what is vasodilation of blood vessels
increased blood flow to the skin which increases heat loss by radiation
what is vasoconstriction of blood vessels
decreased blood flow to the skin which decreases heat loss by radiation
does aestivation require more or less energy than hibernation to maintain a minimum body temperature
less
what is innate behaviour triggered by
an external stimulus such as photoperiod
how may an organism’s metabolic rate be measured?
- measurement of oxygen consumption with a respirometer
- measurement of heat production by with a calorimeter
- measurement of carbon dioxide production with a carbon dioxide probe
what type of circulatory system do birds and mammals have
complete double circulation
put the order of metabolic rates of fish, birds and reptiles from lowest to highest
- fish
- reptiles
- birds
which types of organisms have an internal environment which is dependent on the external environment
conformers
which type of organism can live in wider environmental niche -conformers or regulators?
regulators
why is thermoregulation critical to mammals
mammals need it to maintain optimum temperature for enzyme activity
give two complex compounds sometimes added to culture media to enable certain microorganisms to grow
- vitamins
- amino acids
- fatty acids
why does the death phase occur
accumulation of toxic metabolites or lack of nutrients in the culture media
what is the difference between total and viable cell counts
- total is the living and the dead cells
- viable is only the living cells
give two features of a plasmid that allow it to be an effective vector
- origin of replication
- selectable marker gene
- restriction site
- regulatory sequence
when might you use an artificial chromosome rather than a plasmid
if it is a larger section of DNA you are trying to work with
