Unit 1: Cell Biology
phospholipid bilayer
plasma membrane layers composed of phospholipid molecules arranged with polar heads facing the outside and nonpolar tails facing the inside
cell membrane
double-layer of phospholipids that forms a boundary between a cell and the surrounding environment and controls the passage of materials into and out of a cell
fluid mosaic model
model that describes the arrangement and movement of the molecules that make up a cell membrane
semipermeable membrane
A membrane that allows some molecules to pass through but does not allow other molecules to pass through
diffusion
the process by which molecules move from an area of higher concentration to an area of lower concentration
facilitated diffusion
diffusion of molecules assisted by protein channels that pierce a cell membrane
active transport
energy-requiring movement of molecules across a membrane from a region of lower concentration to a region of higher concentration
phospholipid
molecule that forms a double-layered cell membrane; consists of a glycerol, a phosphate group, and two fatty acids
passive transport
the movement of substances across a cell membrane without the use of energy by the cell
osmosis
diffusion of water molecules across a semipermeable membrane from an area of higher water concentration to an area of lower water concentration
isotonic
Solution that has an EQUAL concentration of dissolved particles compared with another solution
Hypertonic
solution that has a higher concentration of dissolved particles compared with another solution
hypotonic
solution that has a lower concentration of dissolved particles compared with another solution
enzymes
proteins that act as biological catalysts, protein substances that speed up chemical reactions.
catalysts
a substance that decreases activation energy and increases reaction rate in a chemical reaction without being used up or changed.
equilibrium
condition in which reactants and products of a chemical reaction are formed at the same rate
biochemical reactions
Chemical reactions that take place in living organisms (Cellular Respiration, Photosynthesis, etc).
chemical reactions
the process of changing substances into different substances by breaking and forming chemical bonds
viruses
infectious particle made only of a strand of either DNA or RNA surrounded by a protein coat.
RNA
nucleic acid molecule that allows for the transmission o f genetic information and protein synthesis
transcription
process of copying a nucleotide sequence of DNA to form a complementary strand of mRNA...
central dogma
theory that states that, in cells, information only flows from DNA to RNA to proteins.
mRNA
...form of RNA that carries genetic information from the nucleus to the cytoplasm, where it serves as a template for protein synthesis
rRNA
RNA that is in the ribosome and guides the translation of mRNA into a protein; also used as a molecular clock.
nucleus
organelle composed of a double membrane that acts as the storehouse for most of a cell's DNA
endoplasmic reticulum
interconnected network of thin, folded membranes that produce, process,a nd distribute proteins...
golgi apparatus
stack of flat, membrane-enclosed spaces containing enzymes that process, sort, and deliver proteins...
rough endoplasmic reticulum
.parts of the endoplasmic reticulum to which ribosomes are attached on the cytoplasmic side..
mitochondrion
...bean-shaped organelle that supplies energy to the cell and has its own ribosomes and DNA
smooth endoplasmic reticulum
part of the endoplasmic reticulum which does NOT have ribosomes attached, hence it is smooth....
protein
polymer composed of amino acids linked by peptide bonds; folds into a particular structure depending on bonds between amino acids...
photosynthesis
...process by which light energy is converted to chemical energy; produces sugar and oxygen from carbon dioxide and water.
chloroplasts
organelle composed of numerous membranes that are used to convert solar energy into chemical energy; contains chlorophyll.
thylakoid
membrane-bound structure within chloroplasts that contains chlorophyll and other light-absorbing pigments used in the light-dependent reactions of photosynthesis...
light-dependent reactions
part of photosynthesis that absorbs energy from sunlight and transfers energy to the light-independent reactions...
light-independent reactions
part of photosynthesis that uses energy absorbed during the light-dependent reactions to synthesize carbohydrates...
cellular respiration
process of producing ATP by breaking down carbon-based molecules when oxygen is present.
glycolysis
anaerobic process in which glucose is broken down into two molecules of pyruvate and two net ATP are produced...
Kreb's cycle
process during cellular respiration that breaks down a carbon molecule to produce molecules that are used in the electron transport chain...
mitochondria
Plural for mitochondrion.. bean-shaped organelle that supplies energy to the cell and has its own ribosomes and DNA...
ATP
adenosene triphosphate; high energy molecule that contains, within its bonds, energy that cells can use.
electron transport chain
series of proteins in the thylakoid and mitochondrial membranes that aid in converting ADP to ATP by transferring electrons...
protein
polymer composed of amino acids linked by perptide bonds; folds into a particular structure depending on bonds between amino acids...