Bio Chapter 2- Cells Flashcards
Protoplasm
is the living substance of the cell and includes:
Cytoplasm and Karyoplasm
Karoyplasm
simply form the contents of the nucleus
Cytoplasm
Contents of the cell excluding the nucleus
Plasma membrane
Plasmalemma- separates the cytoplasm from its extracellular environment.
Allows cell to maintain homeostasis.
Selective barrier regulate materials into and out of the cell.
Lipid bilayer
Polar head (hydrophilic), attracted to H20. Non polar fatty acyl tail (hydrophobic), directed away from H20. Amphipathic
Fluid Mosaic Model
Lipids and many membrane proteins are in constant lateral motion.
Freeze fracture
Use to study the bilayer. Interior and exterior are not symmetrical.
Endocytosis
Uptake of a molecule and produce a new vesicle from the plasma membrane
Three types of endocytosis
Phagocytosis, Pinocytosis, and Cell mediated endocytosis. All require ATP
Phagocytosis
Cell eating. Engulfing microorganisms, cellular debris and old cells.
Pinocytosis
Cell drinking. Takes in droplets of extracellular fluid which contain solutes.
Cell mediated endocyotosis
Capture of macromolecules using receptor proteins in the cell membrane. Receptor proteins become associated intracellularly using Clathrin.
Exocytosis
Molecules are secreted by the fusion of vesicles with the plasma membrane. Release of contents goes to the ExCS without compromising cell membrane integrity. E.g. Beat cells of pancreas and Nt by synaptic cleft.
Glycocalyx
Carbohydrate chains covalently linked to the transmembrane proteins and/or phospholipids on the outer portion.
Many negatively charged sulfate and carboxyl groups. Involved with making up receptors that participate in functions cell recognition, hormone response, and adhesion.
Plasma membrane functions
1) Physical barrier: inside vs outside
2) Cell communication: receptors
3) Regulates ion and molecule flow
4) Protection and support: maintains cell integrity
Mitochondria
Aerobic respiration
The heart has the most mito, kidneys second.
Inner membrane is highly folded and is a closed space. Outer membrane allows passage.
Mitochondria inner membrane
ETC making 90% of the ATP.
Matrix of the mito is enclosed by the inner membrane.
Mitochondrial Matrix
Kreb Cycle (TCA cycle) and Fatty acid oxidative processes occur. Contains enzymes, ribosomes, and mDNA. Gel like and viscous.
mDNA
Double stranded but circular. Probable ancestral aerobic prokaryotic bacterium. Endosymbiotic Theory.
Mito are self replicating, avg life span of 10 days.
Lysosomes
Membrane bound organelle that contain hydrolytic enzymes used to digest macromolecules.
Neutrophils and macrophages are filled with lysosomes.
Do plants lack lysosomes?
No.
Lysosomes functions
Digest:
a) Microorganisms like fungi or bacteria
b) Cellular debris
c) Old organelles
Lysosome Enzymes
Proteases, nucleases, phosphatases, sulfatases
Inactive at pH 7.2
Phagosome
Formed by the fusion of the cell membrane around microorganism or senescent cell.
Tay Sachs disease
Lysosomal enzyme deficiency Lipids cannot be digested and cells become engorged and neuronal function suffers.
Golgi Apparatus (Complex)
Stacks of membranous sacs that involved the synthesis of carbohydrates and the mod of proteins. Post translational modification and packaging of proteins.
Golgi Apparatus Sections
Cis Golgi: molecules go in
Main Golgi: molecules get processed
Trans Golgi: molecules go outward
Trans Golgi sends to?
Inside the cell: released in vesicles towards lysosomes.
The plama membrane: repair, cell signaling, etc.
Outside the cell: release of hormones as an example.
How are lysosomes formed from the Golgi Complex?
Budding