Enzymes are proteins that act as catalysts for biochemical reactions that take place in organisms.
Correct Answer: Catalyst
Ethanol is a type of alcohol.
Correct Answer: Ethanol
Acetaldehyde is one of the precursors of ethanol.
Correct Answer: Precursor of ethanol
Carbon dioxide is an inorganic compound.
Correct Answer: Inorganic compound
Amino acids are the building blocks of proteins.
Correct Answer: Precursor of protein
The energy of activation is the energy required to start a reaction.
Correct Answer: Energy required to start a reaction
Uneven distribution of a chemical in solution or across a membrane.
Correct Answer: Released by catabolic reactions
A gradient is the uneven distribution of a chemical in solution or across a membrane.
Correct Answer: Uneven distribution of a chemical in solution or across a membrane
Hydrogen bonds stabilize the structure of water and proteins.
Correct Answer: Stabilize water and protein structure
The active site is where enzyme catalysed reactions occur.
Correct Answer: Where enzyme catalysed reactions occur
Pyruvic acid is a product of the catabolism of glucose. The other choices are products of anabolism.
Correct Answer: Pyruvic acid
Energy from ATP is required to synthesize lipoprotein and these are therefore a product of anabolism. The other choices are products of catabolism.
Correct Answer: Lipoproteins generated in membranes
Organisms can be divided into two groups, autotrophs and heterotrophs, based on how they obtain carbon. Autotrophs obtain carbons from CO2.
Correct Answer: CO2
A heterotroph is an organism that cannot use CO2 for growth and instead it uses organic compounds.
Correct Answer: Organic molecules
Metabolism is divided into two parts, anabolism and catabolism. Anabolism is the function of using energy to build organic molecules.
Correct Answer: Energy in the form of ATP is used up
Catabolism is the breakdown of larger molecules into smaller ones. This often results in a release of energy.
Correct Answer: Molecules are broken down
Oxidation is a reaction in which atoms lose electrons and become more positively charged.
Correct Answer: Losing an electron
Redox reactions are coupled reduction and oxidation reactions involving the transfer of electrons so that there is no net loss or gain of electrons. In cells, redox reactions always occur rather than separate oxidation or reduction reactions.
Correct Answer: Electrons are gained and lost
In reduction reactions substances gain electrons and therefore become more negatively or less positively charged.
Correct Answer: Gains an electron and becomes more negatively or less positively charged
In prokaryotes, aerobic cellular respiration yields 36 ATPs per glucose. Fermentation yields 2 ATPs per glucose. In anaerobic respiration, inorganic compounds such as sulphate, nitrate, and ferric iron replace oxygen as electron acceptors. These molecules have a lower reduction potential than oxygen and therefore they produce less energy.
Correct Answer: Aerobic cellular respiration
Facultative anaerobes can carry out metabolic processes either anaerobically or aerobically, whereas strict anaerobic organisms (obligate anaerobes) cannot use oxygen, and strict aerobic organisms (obligate aerobes) must use oxygen.
Correct Answer: Facultative anaerobes
C6H12O6 + 6 O2 → 6 CO2+ 6 H2O + energy
Correct Answer: CO2, water and energy
Enzymes do not cause reactions to happen but increase the rate of reaction. This is due, in part, to lowering the energy of activation by the formation of the enzyme substrate complex.
Correct Answer: Decrease the energy of activation
Full activity of an enzyme often requires either coenzymes or cofactors and these can be prosthetic groups, vitamins, or metal ions.
Correct Answer: All of the choices
Allosteric inhibition occurs when a molecule binds to the enzyme molecule and causes a change in the three dimensional shape of the enzyme molecule. The binding of this inhibitor occurs at a place on the molecule away from the active site. The change in shape means that the substrate can no longer fit properly into the active site. Some allosteric inhibitors bind reversibly and can unbind to allow enzyme activity to resume. If binding is irreversible, the enzyme is permanently disabled.
Correct Answer: Because of conformational changes in the enzyme
Changes in temperature and pH can alter the three dimensional shape of an enzyme, which will alter its activity. If there is less substrate the reaction will proceed more slowly as fewer enzyme-substrate complexes will form. Too much product can inhibit reactions.
Glycolysis directly yields 2 ATP molecules for each glucose molecule. Glycolysis also produces pyruvate which can then be used in aerobic cellular respiration or fermentation. Aerobic catabolism of one glucose molecule, involving glycolysis (2 ATPs), the Krebs cycle (2 ATPs), and the electron transport chain (34 ATPs), yields a total of 38 ATP molecules.
Correct Answer: 2
There are several different fermentation pathways which produce different products: alcoholic fermentation produces ethanol, propionic fermentation produces propionic acid, and butyric-butylic fermentation produces butyric acid. All of these pathways also produce CO2.
This is the simplest fermentation pathway for metabolizing pyruvate. The pyruvate molecule is converted directly to lactate, with NADH being converted to NAD. Unlike most other fermentation pathways, this pathway does not produce gas as a by‐product. Lactic fermentation occurs in several forms of bacteria and is also seen in mammalian muscle cells.
Correct Answer: Produces lactic acid
The Krebs cycle accepts molecules with two carbon atoms. The pyruvate produced from glycolysis has 3 carbons and must have a carbon molecule removed before it enters the cycle.
Correct Answer: Two-carbon molecules
In aerobic respiration the molecule that is the final electron acceptor is oxygen.
Correct Answer: Oxygen
During aerobic respiration 3 molecules of NAD+ carry electrons for every one molecule of FAD. The Krebs cycle and glycolysis produce the electrons which are carried to the electron transport chain.
Correct Answer: NAD+
Anaerobic refers to life without oxygen.
Correct Answer: Oxygen
In prokaryotes, each glucose molecule yields a total of 2 ATP molecules through glycolysis, followed by 36 ATP molecules yielded by the Krebs cycle and electron transport chain, resulting in a total yield of 38 ATP molecules per glucose molecule. In comparison, eukaryotes yield a total of 36 ATP molecules as an additional 2 ATPs are used to move molecules across the mitochondrial membrane.
Correct Answer: 38
The better an organism can metabolize, the better it grows and reproduces, so for pathogens, a good metabolic function makes it more successful at causing disease.
Correct Answer: True
Diagnosis of Helicobacter pylori infection is performed using the urea breath test, no surgery is required.
Correct Answer: False
Iron is an essential cofactor for some enzymes and therefore critical for the growth of microbes containing such enzymes.