C2 Flashcards
CELL MEMBRANE
Plasma membrane = plasmalemma: selectively permeable = semipermeable.
Phospholipid bilayer:
phospho- (polar=hydrophilic), lipid (non-polar=hydrophobic).
Cholesterol
provides rigidity, impermeability.
Proteins
Integral, (mostly transmembrane): in lipid layer. Peripheral: at membrane surfaces.
Glycocalyx
glycoproteins + glycolipids; biological marker (cell recognition, adhesion).
Osmosis
diffusion of water (H2 O) molecules
Movement across membrane
Diffusion
down concentration gradient
CYTOPLASM
CYTOSOL
jelly-like substance: water, ions, enzymes
Transport mechanisms
proteins channels and/or carriers are utilized
Endocytosis
phagocytosis, pinocytosis; receptor-mediated endocytosis (specific). Exocytosis
INCLUSIONS
temporary; ex. lipid, glycogen, melanin)
ORGANELLES
permanent components
Organelles:
organs of the cell
Ribosomes
two subunits of r-RNA + protein, synthesized in nucleolus; protein synthesis
Endoplasmic Reticulum: RER
contains ribosomes; protein synthesis.
Smooth ER
lipid metabolism, breakdown of lipid-based toxins, calcium storage in muscle cells
Golgi
sort, package proteins.
Mitochondria
double membrane, inner membrane with cristae, ATP synthesis.
Lysosomes
acid hydrolases, digest
Peroxisomes
oxidases, catalases neutralize free radicals; liver, kidneys.
Centrioles
paired, 9 microtubule triplets each; form mitotic spindle.
Cytoskeleton
microfilaments (actin), intermediate filaments (tensile strength), microtubules
(movement, maintain cell shape).
NUCLEUS
contains DNA (directs protein synthesis)
Nuclear envelope
2 membranes with nuclear pores; contains DNA (directs protein synthesis).
Chromatin
DNA + protein present during interphase.
Chromosomes
packed DNA units that appear during cell division.
Nucleoli
synthesize ribosomal subunits.
CELL CYCLE
CELL CYCLE = interphase + cell division (mitosis and cytokinesis).
Interphase:
growth, function, DNA as chromatin. In cells that divide: DNA and centriole replication
Cell division:
Mitosis
Mitosis:
1. Prophase: Chromosomes (two chromatids connected by centromere) appear; nucleoli, nuclear
envelope disassemble; centrioles migrate to opposite poles and form mitotic spindle.
2. Metaphase: chromosomes align at cells’ equatorial plane.
3. Anaphase: centromeres split, chromatids pull apart to opposite poles of parent cell.
4. Telophase: reverse of prophase.
Cytokinesis:
actin microfilaments form cleavage furrow, separate cytoplasmic contents into
two daughter cells.