Unit 2 Flashcards Preview

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Flashcards in Unit 2 Deck (54):
1

Vo2 max

The maximum rate at which the body is able to take up and use oxygen

2

Calorimeter

A piece of equipment used to measure heat generation from an organism to allow metabolic rate to be calculated.

3

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

4

Dehydrogenase

An enzyme which removes hydrogen ions and electrons from substrates

5

NAD/FAD

A co-enzyme which easily attaches to hydrogen ions, but releases them when they are required

6

Mitochondria

A structure in the cell responsible for producing energy

7

ATP synthase

An enzyme which produces ATP

8

Fermentation

A type of respiration which takes place in the absence of oxygen

9

Respirometer

A piece of equipment used to measure the rate of respiration

10

Glycolysis

The first stage of respiration where glucose is broken down into pyruvate

11

Anabolic

A reaction which requires energy and builds micromolecules up into macromolecules

12

Catabolic

A reaction which releases energy and breaks down macromolecules into micromolecules

13

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.

14

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.

15

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.

16

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.

17

Structural support

Some membrane proteins are linked to the cytoskeleton and help to maintain the shape of the cell.

18

Biological catalysts

Catalysts made of protein that are only found in living cells

19

Active site

The region of an enzyme molecule where the enzyme acts on the substrate

20

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

21

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

22

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

23

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

24

Metabolite

The intermediates and products of metabolic reactions that take place in organisms

25

Activation energy

The minimum energy required by reactants to allow a reaction to occur

26

Receptor

Cells which monitor changes in environment

27

Effector

Cells, muscles or glands which perform responses to stimuli

28

Hypothalamus

Part of the brain which monitors and regulates temperatures

29

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.

30

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.

31

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.

32

Daily torpor

A period of reduced activity in organisms with high metabolic rates

33

Hibernation

An inactive state resembling deep sleep in which certain animals living in cold climates pass the winter

34

Aestivation

Dormancy in response to high temperature or drought

35

Migrate

A process which avoids metabolic adversity by expending energy to relocate to a more suitable environment.

36

Psychrophiles

Microbes which live in cold environments such as sea ice, and the Arctic and Antarctic peaks

37

Thermophiles

Microbes that live in very hot environments such as deep sea vents and volcanic lakes

38

Dormancy

A condition of biological rest or inactivity characterised by cessation of growth or development and the suspension of many metabolic processes

39

Alkaphiles

Microbes that live in basic environments like soda lakes

40

Halophiles

Microbes that live in very salty environments such as salt lakes and salt mines

41

Acidophiles

Microbes that live in acidic environments such as sulphur springs.

42

Extremophiles

An organism which is able to live in extreme conditions.

43

Restriction endonuclease

An enzyme that cuts specific target sequences of DNA

44

Ligase

An enzyme which joins fragments of DNA together

45

Wild type

Describes the phenotype of the typical form of a species as it occurs in nature

46

Heterotrophic

An organism which gains energy by consuming other organisms

47

Complex media

Contain one or more crude sources of nutrients and their exact chemical composition and components are unknown

48

Defined media/synthetic media

Media in which the components of the medium are chemically known and are present in relatively pure form

49

Nutrient medium

A mixture of nutrients, includes carbon/nitrogen, required for growth

50

Lag phase

Microorganisms adjust to the conditions of the culture by producing enzymes that metabolise the available substrates

51

Exponential/logarithmic phase

The rate of growth is at its highest

52

Stationary phase

The culture medium becomes depleted and secondary metabolites are produced

53

Death phase

Lack of substrate and the toxic accumulation of metabolites causes death of cells

54

Archaea

A group of single-celled microorganisms