UNIT - Metabolism and Survival Flashcards
Anabolic Reaction
Involves simple substances being built up to form larger more complex molecules. This requires ATP/energy.
Catabolic Reaction
Involves the breakdown of larger more complex molecules into simpler substances. This releases ATP/energy.
Cell Membrane
Boundary between the cell contents and external surroundings of the cell, it regulates the movement of materials into and out of the cell. It is composed of proteins and phospholipids (arranged in a phospholipid bilayer).
Activation Energy
The minimum energy required for chemical molecules to react successfully within a cell.
Induced Fit
When an enzyme changes shape slightly to fit more closely to the substrate, increasing the rate of reaction.
Competitive Inhibitors
These are inhibitors that act by binding to the active site of an enzyme preventing the substrate from binding. This can be reversed by increasing the concentration of the substrate.
Non-Competitive Inhibitors
These are inhibitors that work by binding to a site called the allosteric site. This changes the shape of the active site meaning the substrate can no longer bind. This is irreversible.
Feedback Inhibition
This occurs when an end product inhibits the activity of an enzyme that catalysed a reaction earlier in the pathway that produced the end product.
Glycolysis
The breakdown of glucose to pyruvate in the cytoplasm (both an aerobic and anaerobic process).
Co-enzyme A
Combines with acetyl group to form acetyl-co-enzyme A and enters the citric acid cycle.
Dehydrogenase Enzymes
Enzymes that remove H ions and electrons.
Final Hydrogen Acceptor in Respiration
Oxygen which combines the Hydrogen to form water.
Alternative Respiratory Substrates
Other sugars (broken down into glucose or intermediate of glycolysis), Fat (broken down to fatty acids and glycerol), Protein (broken down into amino acids).
Single Circulatory System
Found in fish where there is only one atrium and ventricle. Blood passes through the heart once so it loses pressure.
Incomplete Double Circulatory System
Found in Reptiles and Amphibians. Blood passes through the heart twice but as there is only one ventricle there is the mixing of oxygenated and deoxygenated blood so the blood delivered to cells is incompletely oxygenated.
Complete Double Circulatory System
Found in mammals and birds. The heart has two atria and ventricles with a wall completely separating the oxygenated and deoxygenated blood. This is the most efficient oxygen delivery system.
VO2 Max
The measure of the peak volume of O2 you can consume and use in a minute.
Conformer
Animal that cannot maintain metabolic rate using physiological mechanisms and rely directly on their external environment to regulate their internal environment. This means they have a low metabolic cost but can only occupy a narrow range of ecological niches.
Regulator
Animal that can maintain its metabolic rate using physiological mechanisms (homeostasis). This requires large amounts of energy and they have a large metabolic cost but means they can occupy a large range of ecological niches.
Predictive Dormancy
This dormancy occurs before the onset of the adverse conditions. Normally genetic and occurs in places with predictable seasons where it can be triggered by environmental cues such as temperature and photoperiod.
Consequential Dormancy
This dormancy occurs after the onset of adverse conditions. A response to an unpredictable environment eg. High altitudes.
Hibernation
Form of Dormancy employed by many mammals in response to winter and lack of food. The mammal will reduce its metabolic rate by lowering heart rate, breathing rate and body temperature. This will reduce the energy requirements during the harsh months of winter allowing them to survive.
Aestivation
Allows some animals to survive periods of high temperature and drought. Often the animal burrows into the ground where it is cooler and may secrete mucus to cover their body giving them a layer of moisture.
Daily Torpor
Small birds and mammals with a high metabolic rate will go into a state of torpor for periods during the day to reduce their metabolic cost.
Migration
A behaviour used to avoid adverse conditions. This involves the long term movement of individuals, usually taking place on a seasonal basis.
Extremophiles
Organisms that live in extreme conditions where most others would be unable to survive.
Lag Phase
Enzyme Induction- the microorganisms adjust to their conditions and produce the enzymes necessary to use the available substrate for their metabolic processes.
Log/Exponential Phase
Population doubles with each successive cell division.
Stationary Phase
Food source has been used up and oxygen is in short supply. Toxic metabolites may be released. The production of new cells equals the rate of cell death resulting in no increase in population.
Death Phase
The lack of usable substrate and the accumulation of high concentrations of toxic metabolites causes the death rate to be higher than birth rate so population decreases.
Precursor
Substance which is acted on by an enzyme to ensure that a desired metabolite is produced later in the same pathway.
Inducer
Substance which triggers the production of a specific enzyme which then produces the required metabolite.
Mutagenesis
Process of inducing mutations in a microorganism.
Restriction Site
Location on the plasmid that can be cut open for the insertion of the required human gene.
Origin of Replication
The area on the plasmid that contains all the genes necessary for self replication which is essential if the plasmid is to make copies of itself.
Marker Genes
A gene which is deliberately transferred along with the required gene on the plasmid. It is easy to recognise and can be used to identify cells to which the gene has been successfully transferred to. There are two types- gene for antibiotic resistance or gene which makes cells containing the recombinant DNA look different.
