Unit 2 Flashcards
Vo2 max
The maximum rate at which the body is able to take up and use oxygen
Calorimeter
A piece of equipment used to measure heat generation from an organism to allow metabolic rate to be calculated.
Citric acid/Krebs cycle
The second stage of respiration, where acetyl CoA and oxaloacetate join to form citric acid and a series of reactions which return citric acid to oxaloacetate
Dehydrogenase
An enzyme which removes hydrogen ions and electrons from substrates
NAD/FAD
A co-enzyme which easily attaches to hydrogen ions, but releases them when they are required
Mitochondria
A structure in the cell responsible for producing energy
ATP synthase
An enzyme which produces ATP
Fermentation
A type of respiration which takes place in the absence of oxygen
Respirometer
A piece of equipment used to measure the rate of respiration
Glycolysis
The first stage of respiration where glucose is broken down into pyruvate
Anabolic
A reaction which requires energy and builds micromolecules up into macromolecules
Catabolic
A reaction which releases energy and breaks down macromolecules into micromolecules
Selectively permeable
A property of a membrane which means that substances do not freely pass through it. The membrane allows the passage of certain small molecules, but excludes many other molecules.
Channel/pore proteins
These proteins allow specific molecules and ions to pass through the membrane, for example, a protein channel found in the plasma membrane allows chloride ions to pass through the membrane.
Carrier/pump proteins
As the name suggests, carrier proteins bind to specific molecules or ions temporarily, enabling them to cross the membrane. This involves a change to the conformation of the carrier protein, which may require energy provided by ATP. The sodium-potassium pump is an example of a carrier protein.
Enzymes
Some proteins in the membrane catalyse a specific reaction. Some receptor proteins have enzymatic activity, in which the cytoplasmic portion of the protein catalyses a reaction in response to binding by a ligand.
Structural support
Some membrane proteins are linked to the cytoskeleton and help to maintain the shape of the cell.
Biological catalysts
Catalysts made of protein that are only found in living cells
Active site
The region of an enzyme molecule where the enzyme acts on the substrate
Induced fit model
A model of an enzyme-substrate reaction that causes a conformational change in the active site of the enzyme that allows the substrate to fit perfectly
Competitive inhibition
Competitive inhibition of enzyme activity occurs when an inhibitor, resembling the structure of the substrate, binds to the active site of the enzyme and blocks the binding of the substrate
Non-competitive inhibition
A molecule binds to a part of the enzyme away from the active site, and causes a conformational change in the active site of the enzyme, thereby inhibiting the binding of the appropriate substrate molecule
Feedback inhibition
Regulation of the enzyme activity where the first enzyme of a metabolic pathway is inhibited but the reversible binding of the appropriate substrate molecule
Metabolite
The intermediates and products of metabolic reactions that take place in organisms
Activation energy
The minimum energy required by reactants to allow a reaction to occur
Receptor
Cells which monitor changes in environment
Effector
Cells, muscles or glands which perform responses to stimuli
Hypothalamus
Part of the brain which monitors and regulates temperatures
Vasodilation
Enlargement in diameter of a blood vessel, thus increasing blood flow. The blood vessels (arterioles) that supply blood to the skin dilate/widen, increasing the amount of blood flowing to the skin. This increases the surface area from which heat can be lost to the environment by radiation.
Vasoconstriction
Contration in diameter of a blood vessel, thus increasing in blood flow. The arterioles that supply blood to the skin constrict/narrow, reducing the amount of blood flowing to the skin. As a result less heat is lost by radiation from the surface of their body.
Negative feedback
Homeostasis; the process by which an increase in one factor cause a decrease in another factor, thereby maintaining equilibrium around a set point/norm.
Daily torpor
A period of reduced activity in organisms with high metabolic rates
Hibernation
An inactive state resembling deep sleep in which certain animals living in cold climates pass the winter
Aestivation
Dormancy in response to high temperature or drought
Migrate
A process which avoids metabolic adversity by expending energy to relocate to a more suitable environment.
Psychrophiles
Microbes which live in cold environments such as sea ice, and the Arctic and Antarctic peaks
Thermophiles
Microbes that live in very hot environments such as deep sea vents and volcanic lakes
Dormancy
A condition of biological rest or inactivity characterised by cessation of growth or development and the suspension of many metabolic processes
Alkaphiles
Microbes that live in basic environments like soda lakes
Halophiles
Microbes that live in very salty environments such as salt lakes and salt mines
Acidophiles
Microbes that live in acidic environments such as sulphur springs.
Extremophiles
An organism which is able to live in extreme conditions.
Restriction endonuclease
An enzyme that cuts specific target sequences of DNA
Ligase
An enzyme which joins fragments of DNA together
Wild type
Describes the phenotype of the typical form of a species as it occurs in nature
Heterotrophic
An organism which gains energy by consuming other organisms
Complex media
Contain one or more crude sources of nutrients and their exact chemical composition and components are unknown
Defined media/synthetic media
Media in which the components of the medium are chemically known and are present in relatively pure form
Nutrient medium
A mixture of nutrients, includes carbon/nitrogen, required for growth
Lag phase
Microorganisms adjust to the conditions of the culture by producing enzymes that metabolise the available substrates
Exponential/logarithmic phase
The rate of growth is at its highest
Stationary phase
The culture medium becomes depleted and secondary metabolites are produced
Death phase
Lack of substrate and the toxic accumulation of metabolites causes death of cells
Archaea
A group of single-celled microorganisms
