metabolic pathways Flashcards
what is metabolism
Metabolism is the term used to describe the enormous number of integrated and complex biochemical reactions that occur in an organism.
which reaction releases energy?
a) annabolic
b) catabolic
b)
which reaction builds up small molecules into larger ones?
a) annabolic
b) catabolic
a)
what is the function of Channel (pore) proteinsin the plasma membrane?
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 (Cl-) to cross the membrane.
what is the function of Carrier (pump) proteins in the plasma membrane?
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 involved in the transport of ions.
what is the function of Enzymes in the plasma membrane?
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.
what is the function of Structural support in the plasma membrane ?
some membrane proteins are linked to the cytoskeleton and help to maintain the shape of the cell.
what is a metabolic pathway ?
A metabolic pathway is a sequence of reactions that is controlled by enzymes that change one metabolite to another.
how are metabolic pathways controlled?
Metabolic pathways are controlled by altering the presence and/or activity of key enzymes within the pathway
how do problems occur in metabolic pathways ?
Problems occur in metabolic pathways if the enzymes are not synthesised correctly, due to mutations in the genes that code for them. The next reaction in the pathway is then unable to occur and the intermediate metabolite builds up in the system.
what is activation energy?
the energy required to initiate the reaction
the enzyme _______ the activation energy
a) decreases
b) increases
a)
what are competitive inhibitors?
a molecule that binds at the active site preventing the substrate from binding.
how can we reverse competitive inhibition ?
by increasing the concentration of the correct substrate in the reaction.
what are non-competitive inhibitors ?
a molecule that binds away from the active site but change the shape of the active site preventing the substrate from binding.
