Definitions Flashcards
catalyst
substance that speeds up chemical reactions without being used up in the reaction
cellular metabolism
all of the chemical reactions occurring in a cell
intracellular enzymes
occur inside cells. They speed up and control metabolic reactions.
extracellular enzymes
are produced by cells. They work outside the cell, e.g. digestive enzymes break down food in the small intestines.
anabolic reactions
Reactions that start with simple molecules and use energy to build more complex molecules are called anabolic reactions. For example, amino acids form a polypeptide chain. ENDERGONIC. Cells use the available energy released from catabolic reactions to fuel anabolic reactions.
catabolic reactions
Reactions that breakdown complex molecules to simpler fragments, releasing energy are called catabolic reactions. For example, starch polymer breaking down to simple glucose monomers. EXERGONIC
endergonic reaction
In endergonic reactions, a total net amount of energy is absorbed and locked up in the new bonds of the products.
These have more stored energy than the reactants.
exergonic reaction
In exergonic reactions, a total net amount of energy is released from the bonds of the reactants and the products have less energy than the reactants.
biochemical process
A biochemical process or reaction occurs when the chemical bonds of inputs or reactants are broken and the atoms recombine to form a new substance or substances, output or products.
enzyme
type of protein that like all proteins, have a specific shape.
active site
precise place on an enzyme’s surface to which the substrate can become attached
cell theory
all living things are composed of one or more cells and all cells come from pre-existing cells
prokaryote cell
the simplest type of cells, exist as single cells with no membrane bound organelles
eukaryote cell
complex cells with membrane bound organelles
golgi apparatus
system of membranes that package and store substances before their release (ANIMAL)
temporary vacuole
a temporary storage sac (ANIMAL)
endoplasmic reticulum
intra/intercellular transport system (ANIMAL)
ribosome
site of protein synthesis (ANIMAL)
plasma membrane
outermost barrier of the cell, selectively allows some substances to pass through it (ANIMAL and PLANT)
nucleus
coordinates all the activities of the cell (ANIMAL and PLANT)
nucleolus
dark staining structure within the nucleus. One or more can be seen in cells when they are not dividing. Is responsible for the synthesis of ribosomal RNA and the assembly of ribosomes from ribosomal RNA and proteins (ANIMAL and PLANT)
mitichondrion
site of cellular respiration (ANIMAL and PLANT)
cytoplasm
fluid material where activities of the cell occur (ANIMAL and PLANT)
cell wall
provides extra support and protection to plant cells (PLANT)
large permanent vacuole
fluid filled space that stores various materials (PLANT)
chloroplast
site of photosynthesis and stores carbohydrates. They have their own genetic material (DNA +RNA) and ribosomes that are similar to that of prokaryotes - reflecting their evolutionary link with them (PLANT)
chlorophyll
Chlorophyll is a green pigment found in chloroplasts that is able to absorb light energy and to make it available for use in photosynthesis
ATP
Adenosine triphosphate - an energy storage molecule that is used to power cellular processes.
organic
complex, carbon - containing compound
inorganic
compound that is not organic - simpler carbon compounds i.e. CO2, CO, CaCO3
monomer
small molecule that acts as a building block for macromolecules
polymer
large molecule built up from linking small molecules together i.e. proteins, nucleic acids and complex carbohydrates
proteome
a complete set of proteins produced by a cell.
gene
segment of DNA used to make a polypeptide via mRNA. mRNA is a temporary copy of a gene that contains information to make the polypeptide
