1 - BIOCHEMISTRY AND THE ORGANIZATION OF CELLS Flashcards
Biochemistry describes the molecular nature of life processes. In living cells, many chemical reactions take place simultaneously.
Hundreds
or thousands of these smaller molecules, or monomers, can be linked to produce
macromolecules, which are also called?
macromolecules formed by the bonding of smaller units
Polymers
amino acid combine by polymerization to form?
Proteins
Nucleotides combine to form?
Nucleic acid
Polymerization of sugar monomers produces?
Polysaccharides
Proteins of the class called enzymes display
catalytic activity, which means that they increase the rates of chemical reactions compared with uncatalyzed reactions.
is the relationship between the nucleotide sequence in
nucleic acids and the amino acid sequence in proteins
Genetic code
the total DNA of a cell
Genome
Individual units of heredity, controlling individual traits by coding for a functional protein or RNA
responsible for the transmission of inherited traits, are part of the DNA found in each chromosome
Genes
most resemble the earliest cells
(karyon, “kernel, nut”) = before the nucleus
include bacteria and cyanobacteria
single-celled organism, but groups of them can exist in association
Prokaryotes
“true nucleus”
more complex organisms and can be multi-cellular and single-celled
single-celled = yeast and Paramecium
multi-celled = animals and plants
Eukaryotes
part of the cell that has a distinct function; it is surrounded by its own membrane within the cell
a membrane-enclosed portion of a cell with a specific function
Organelle
where the DNA of the cell is concentrated in one region; directs the workings of the cell
Nuclear region
particles consisting of RNA and protein; sites of protein synthesis in all living organisms, are frequently bound to the endoplasmic reticulum in eukaryotes
RIbosomes
portion of the cells outside the nucleus
Cytoplasm
aqueous portion of the cell that lies outside the membrane-bounded organelles
fluid portion of the cell outside the nuclear region
Cytosol
extensions of the plasma membrane, rather than in chloroplasts
Chromatophores
RNA + protein; sites of protein synthesis in all organisms
Ribonucleoprotein particles
an assemblage of lipid molecules and proteins
Cell membrane/plasma membrane
made up mostly of polysaccharide material
outer coating of bacterial and plant cells
Cell wall
Prokaryotes have a nuclear region, which contains DNA, and ribosomes,
the site of protein synthesis, as their main features. They have a cell membrane, but do not have an internal membrane system.
contains most of the DNA of the cell and is the site of RNA synthesis
most important eukaryotic organelle
location of the main genome
responsible for storing the cell’s DNA and for coordinating important cellular activities
Nucleus
contains enzymes that catalyze important energy-yielding reactions
respiratory organelles
Mitochondria
found in green plants and green algae; sites of photosynthesis
has its own DNA
Chloroplasts
Both mitochondria and chloroplasts contain DNA that
differs from that found in the nucleus, and both carry out transcription and
protein synthesis distinct from that directed by the nucleus.
mostly made up of the polysaccharide cellulose, giving the cell its shape and mechanical stability
have cell walls
Plant cell
have neither cell walls nor chloroplasts; same is true for some protists
Animal cell
what surrounds the nucleus?
Nuclear double membrane or nuclear envelope
part of the nucleus that is rich in RNA
Nucleolus
an aggregate of DNA and protein
a complex of DNA and protein found in eukaryotic nuclei
Chromatin
has a double membrane and is the second very important eukaryotic organelle
site of energy-yielding oxidation reactions
has its own DNA
an organelle that contains the apparatus responsible for aerobic oxidation of nutrients
Mitochondrion
the inner membrane of the mitochondrion exhibits many folds
folds in the inner mitochondrial membrane
Cristae
the space within the inner membrane
part of a mitochondrion enclosed within the inner mitochondrial membrane
Matrix
part of a continuous single-membrane throughout the cell
attached to the cell membrane and to the nuclear membrane
a continuous single-membrane system throughout the cell
Endoplasmic reticulum
studded with ribosomes bound to the membrane
site of protein synthesis
Rough endoplasmic reticulum
does not have ribosomes bound to the membrane
Smooth endoplasmic reticulum
where chloroplasts are found; specialized structures
Grana (singular granum)
separate from the endoplasmic reticulum but is frequently found close to the smooth endoplasmic reticulum
series of membranous sacs
involved in the secretion of proteins from the cell, but it also appear in cells in which the primary function is not protein synthesis
it is the site in the cell which sugars are linked to other cellular components, such as proteins
a cytoplasmic organelle that consists of flattened membranous sacs, usually involved in secretion of proteins
Golgi apparatus
membrane-enclosed sacs containing hydrolytic enzymes that could cause considerable damage to the cell if they were not physically separated from the lipids, proteins, or nucleic acid that they are able to attack
Lysosomes
contain enzymes involved in the metabolism of hydrogen peroxide (H2O2) which is toxic to the cell
Peroxisomes
found in plant cells only
contain the enzymes that catalyze the glyoxylate cycle, a pathway that converts some lipids to carbohydrate with glyoxylic acid as an intermediate
Glyoxysomes
Separates the cell contents from the outside world;
contents include organelles (held in place by the
cytoskeleton*) and the cytosol
Cell membrane
rigid exterior layer of plants
Cell wall