2.1 Cell Flashcards
(31 cards)
if a cell were put into a hypertonic solution then
water would pass through the plasma membrane faster than in.
Glycerophospholipids contain:
a glycerol linked to two fatty acyl groups and one phosphate group
Shingolipids contain:
a sphingosine linked to one fatty acyl group. Occur primarily in the outher face of the plasma membrane in eukaryotes.
Lysophospholipids
have one fatty acyl group removed, cuting the ratio of nonpolar to polar structure in half. Promotes conversion of phospholipid bilayers into micelles and may destabilize membranes
Addition of cholesterol to a lipid bilayer:
reduces fluidity of the lipids and reduces penetration of small polar molecules across the bilayer.
Osmosis
Simple diffusion of water from areas of lower solute concentration (hypotonic) to areas of higher solute concentration (hypertonic)
Three essential components of eukaryotic chromosomes are:
- a centromere sequence 2. at least one repliication initiation sequence 3. a telomere sequence
Telomere sequence
simple repeated sequences added tot he ends of chromosome to allow replication without loss of genetically critical sequence.
Centromere sequence
needed to integrate the chromosome into the spindle during mitosis or meiosis
Free ribosomes
proteins are made on free ribosomes
Smooth Endoplasmic Reticulum
Consists of irregular tubes and flattened sacs of membrane. Has a role in synthesis of phospholipids and steroids, and detoxifying many foreign molecules.
Rough Endoplasmic Reticulum
Site of synthesis of proteins that will be ‘packaged’ by the Golgi bodies. Initial oligosaccharide groups are aded to glycoproteins.
Golgi bodies
Transfers proteins from Cis face (rough ER side) to Trans face (cell membrane). Lysomal enzymes are also transported to lysosomes.
Lysosomes
Contains hydrolytic enzymes that digest material.
Mitochondria
Involved in ATP generation, steroid synthesis and interconversion. Are genetically autonomous
Microfilaments
actin protein subunits. usually associated with myosin. Capable of contraction.
Microtubules
Contains alpha and beat tubulin proteins. Support cell shape or surgace to move organelles.
Intermediate filaments
mechanically link desmosomal (macula adherens) cell to cell junctions
Peroxisomes
Typically contain catalase, which generates hydrogen peroxide to detoxify. Involved in beta oxidation of fatty acids.
Types of Cell to Cell Junctions
- Occluding junctions of zonula occludens 2. Attachment junctions 3. Communication junctions
Occuluding junctinos
Outer layers of plasma membranes of associated cells appear fused.
Zonula occludens
This complex usually occurs as a band around the apical ends of epithelial cells. (fused cell membranes)
Types of attachment junctions:
- Zonula adherens 2. Macula adherens
Zonula adherens
Typically occur adjacent to zonula occludens jenctions. Attaches cells by a band of dense material in the intercellular space.
