CELLULAR METABOLISM Flashcards
What is cellular metabolism?
- is the collection of all chemical reactions that occur in the body.
What are anabolism and catabolism?
- Anabolism: small molecules are built up into larger ones (requires energy)
- Catabolism: larger molecules are broken down into smaller ones (releases energy)
What does anabolism do?
- provides all the materials a cell requires for maintenance, growth and repair.
What is hydrolysis responsible for?
Digestion
What is intermediary metabolism?
- refers to the processes that obtain, release, and use energy.
What is primary metabolites?
- are products of metabolism essential to survival
What are secondary metabolites?
- are not essential for survival, but may provide an advantage or enhancement
What type of energy is needed for metabolic reactions?
- Activation energy
What do enzymes do in metabolism?
- Enzymes control rates of both catabolic and anabolic reactions by acting as catalysts to bring about specific biochemical changes
What are the general functions of enzymes in metabolism?
- temporarily bind to and bring together reacting molecules so they are in the best position for chemical interactions resulting in the formation of a product.
What is a substrate?
- a substrate is a molecule that only binds to a particular enzyme
- many substrates have “are” after.
Example: lipase catalyzes a reaction that breaks down a lipids
What is an enzyme’s active site?
- a part of the enzyme molecule where substrates temporarily attach - forming an enzyme-substrate complex
- this alters the shape of the enzyme slightly to form a precise fit to the substrate
- the product forms and the enzyme releases the substrate and can then be reused
What is a metabolic pathway?
- a sequence of enzyme-controlled reactions that lead to the synthesis or breakdown of a particular biochemical
What is a regulatory enzyme?
- an enzyme that catalyzes one step sets the rate for the entire sequence of reactions.
What is a rate-limiting enzyme?
- enzymes that become saturated when the substrate concentration exceeds a certain level.
- The first in the series of reactions that comprises the metabolic pathway
What are cofactors/coenzymes?
- some enzymes only become active when they combine with a nonprotein component called a “cofactor”
- the cofactor helps the active site fold into it’s appropriate conformation
- may be an ion, such as copper, iron or zinc. Or a small organic molecule called a COENZYME
What is denaturation?
- Exposure to excessive heat, radiation, electricity, fluids with extreme pH values, or certain chemicals can denature, or alter, the conformation of an enzyme or inactivate it that makes the enzyme nonfunctional
How do enzymes “recognize” their substrates?
- a substrate is a specific type of molecule that a certain enzyme can act on.
- It recognizes the substrate by the unique 3D shape, or conformation of the enzyme.
What is a cofactor?
- a nonprotein molecule that must combine with an enzyme in order to activate it.
- Ion, or an organic molecule or vitamin
What is a coenzyme?
- A small organic molecule such as a vitamin that acts as a cofactor.
- Both help the enzyme catalyze a chemical reaction
What is energy in metabolic reactions?
- energy is the capacity to change something; it is the ability to do work
What are common forms of energy?
- heat, light, sound, electrical, mechanical, and chemical energy
- chemical energy is the most abundant within the body
Where is chemical energy held?
- Is held in the bonds between the atoms of molecules and is released when these bonds break
What is oxidation?
- the loss of hydrogen atoms (with their electrons) from molecules such as glucose, resulting is loss or release of energy
What percent of energy do cells capture from the breaking of chemical bonds in cellular Respiration?
- About 40%
What is ATP?
- Is the primary energy carrying molecule within a cell
- Carries energy in a form that a cell can use
- Stores high amounts of energy in it’s phosphate bonds
What does ATP consist of?
- an adenine, a ribose and a three phosphates chain
What is an ADP?
- an ATP molecule that has lost it’s terminal end and is now left with two phosphate molecules
