3- Dynamic Cells: Biochmical Pathways Flashcards
Acetyl CoA
A 2 carbon compound that is a substrate for the cytochrome acid cycle. It is formed from pyruvate during glycolysis and from the degradation of fatty acids and some amino acids.
Activation energy
The amount of energy that must be possessed by a reactant before it reacts.
Active site
The place on an enzyme molecule that the substrate binds to
ADP
Adenosine di-phosphate, the molecule that when combined with energy and a phosphate forms ATP
Aerobic respiration
Cellular respiration occurring in an oxygen rich environment, leads the the production of 36ATP, CO2 and H2O
Alcohol fermentation
The anaerobic respiration that takes place in yeasts, it produces ethanol and energy(small amounts)
Anabolic reactions
Reactions that build up an molecules
Anaerobic
A biological process that occurs with out the presence of oxygen
Antioxidant
Compound that neutralise oxidants, which are produced when cells in the body burn oxygen to produce energy; oxidants can clog arteries and contribute to cancer, diabetes and other diseases; antioxidants, found in fruits and vegetables, contribute to good health
Autotroph
An organism that makes its own food from light energy or chemical energy without eating; most green plants, many protists and many bacteria are autotrophs
Biochemical pathway
A chemical reaction in a living cell that proceeds via a series of intermediate compounds to the final product
C3 Plants
The type of photosynthesis carried out by most plants in which a three carbon compound, Phosphoglycerate, is the first stable product of carbon fixation; this occurs during the first step of the Calvin benson cycle
C4 Plants
The type of photosynthesis found in tropical grasses in which a four carbon compound, malate, is the first stable product of carbon fixation; carbon dioxide is later drawn out of the malate and into the Calvin benson cycle rather than directly from air
Calvin-Benson cycle
A series of biochemical reactions taking place in the chloroplasts of photosynthetic organisms; these light-independent reactions occur in the stroma, where energy from the light-dependent reactions is used to fix carbon dioxide and convert it into sugar.
CAM plants (Crassulacean Acid Metabolism plants)
These plants use an enzyme to fix carbon dioxide at night, generating a four carbon compound, malate, which is broken down during the day to release carbon dioxide, which enters the Calvin benson cycle
Carbon fixation
The use of atmospheric carbon dioxide and its conversion into carbohydrates; this process occurs in the stroma of chloroplasts in eukaryotic cells
Catabolic reactions
Reactions such as cellular respiration that involve the breakdown of complex molecules to simpler products
Cellular metabolism
All chemical processes occurring within a living cell
Chlorophyll
A green pigment molecule that also absorbs red light to become ionised; the highly energised electrons generated in this house process are donated to organic molecules and ATP is produced, yielding chemical energy from light energy.
Chloroplast
A double membrane organelle that is found in the cytoplasm of plants and algae which contains chlorophyll and the enzymes necessary to carry out photosynthesis
Coenzyme
A small organic cofactor molecule that plays an important role in enzyme-catalysed processes; it may function as a carrier, donor or acceptor of a substance involved in the reaction and/or it may bind with an enzyme to activate it
Cofactors
Various substances , such as mineral ions and vitamins, that need to be present in addition to an enzyme to catalyse a certain reaction
Competitive inhibitor
A substance that binds to the active site of an enzyme to compete with the substrate
Cristae
Infolding of the inner membrane into the matrix of the mitochondria, thus increasing the total surface are of the inner membrane; components of the electron transport chain are located
Cytochromes
Membrane bound proteins that carry our electron transport; they are located in the mitochondrial inner membrane and in chloroplasts
Electron transport system
Process involving the stepwise transport of electrons to a final electron acceptor, such as oxygen(in aerobic respiration); ultimatly, it creates an electrochemical gradient across membranes to drive the phosphorylation of ADP to yield ATP
Endergonic reaction
An energy-requiring chemical reaction
Endosymbiotic theory
A theory that suggests that chloroplasts and mitochondria arose from scientists bacteria that were ingested by eukaryotic host cells about a billion years ago
Enzyme
A specific protein catalyst that acts to increase the rate of reaction within the cell by losing the amount of activation energy required for the reaction to take place.