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Patho Chapter 4
Functional Components of the Cell
- Nucleus - controls cell function
- Cytoplasm - contains organelles and cytoskeleton
- Ribosomes - protein synthesis
- Er - transport substances; Er makes protein; Smooth makes carb and lipid
- Golgi bodies - modify material synthesized in
- Lysosomes -hydrolytic enzymes that digest worn out cell parts and foreing bodies
- Proteasome - digests misformed and misfolded proteins
- Mitochondria - turns food into ATP
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whats in cytoplasm
- microtubules - slender, stiff, incluence cell cell shape
- microfilaments - thin, indlude actin and myosin
- plasma membrane - lipid bilayer
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Protein Synthesis
- Messenger RNA (mRNA) copies and carries the DNA instructions for protein synthesis to the cytoplasm
- Ribosomal RNA (rRNA) is the site of protein synthesis
- Transfer RNA (tRNA) transports amino acids to the site of protein synthesis for incorporation into the protein being synthesized.
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Cell communications via
- chemical messanger system
- chemical messagers moe from cell to cell through gap junction without entering extracellular fluid
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cell communicaiton
chemical messangers bind to receptors on or near cell surface
- -G protein linked receptors - G proteins that function as an off switch to convert external signals into
- -ion channel linked signaling - mediated by neurotransmitters that open or close ion channels
- - enzyeme linked receptors - interact with peptide hormones like insuline and growth factors to initiate activity of the intracellular protein tyrosine kinase enzyme
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cell cycle
- G0 - resting phase
- G1 - prepares cell for dividion through DNA and protein synthesis
- S - synthesis phase, DNA replication
- G2 - pre-mitotic phase (RNa and protein synthesis)
- M - cell dividion
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cell metabolism and energy sources
- carbs, fats, protein broken down;
- energy converted into ATP
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two sites of energy conversion
- - anaerobic glycolic pathway
- glucose to ATP, can f(x) withouth oxygen by producing lactic acid
- - aerobic pathway
- most effecient is citric acid cycle and electron transport chain in the mitochondria
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movement of substances across the cell memebrance
- passive transport process
- active transport process
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passive transport process
- do not required any energy
- - diffusion: a process by which substances such as ions jmove from an area of greater concentration to one of lesser concentration
- - simple diffusion
- - osmosis: the diffusions of water molecules through a semipermeable membrane along concentration gradient
- - fascilitated diffusion (mediated passive transport): passive process, in which molecules that cannot normally pass through the cell's membrane do so with the assitance of a carrier molecule
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active transport processes
- require the metabolic energy by the cell
- - transport by pumps: na+/k+ - atpase pump
- - transport by vescicles
- - endocytosis: process by which cells engulf materials from surrounding medum
- phagocytosis
- pinocytosis (lipids), small particules
- -exocytosis: the removal of large particles from the cell and is essentially the reveerse of endocytosis
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membrane potential
- difference in electric potential between the inside and outside of a cell across its membrane
- typically -70 millivolts
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restring membrane potential
baseline potential of a cell when it is not actively transmitting signals
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action potential
- transient change in membrane potential that allows for the transmission of signals along the cell membrane
- rapid depolarization followed by repolarization
- influx of possitively charged ion (Na+)
- repolarization phase (efflux of K+)
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3 primary germ layers
- ectoderm
- mesoderm
- endoderm
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ectoderm
- epidermis, hair, nails, glands of skin
- brain and spinal cord
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mesoderm
- notochord - (nucleus of intervertebral discs)
- somite - solertome (vertebrae and ribs), dermatome (dermis of dorsal body region), mytome trunk and limb musculature
- intermediate - kidneys and gonads
- somatic mesoderm - parietal serosa, dermis of ventral body region, connective tissue of limbs (bvones and joint and ligaments)
- splanchnic mesoderm - wall of digestive and respiratory tracts , visceral serocas, heart, and blood vessels
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endoderm
epithelial lining and glands of digestive and respiratory tracts
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simple squamous epithelium
air sacs of lungs
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