Eukarea.txt

• author "me"
• fileName "Eukarea"
• tags "Biology, Euk, "
• description ""
• Def necleolus
• Region within the nucleus where rRNA is transcribed and Ribosomes assemble

• Endocytosis: 1 method for cellular uptake of extracellular material
• 1. Phagocytosis: eating, typically receptor mediated, few cells have capability
• 2. Pinocytosis: drinking, more common, non-selective/specific uptake

Exocytosis: opposite of endocytosis

• Structure: membrane bound organelle that is contiguous in regions with nuclear and cellular membrane
• Location: rough ER close to nucleus, SER is distal to the nucleus
• Fxn: RER to make all proteins which do not act in cytosol; SER make lipids, cholesterol, and steroids, minor detox

Golgi: membrane bound organelle which functions in organising and shipping protein received from rough ER

Intracellular vessicle which contains low pH and hydrolitic enzymes for macromolecular degradation. Used for both extra a and intracellular molecular degradation

• It is a cytosolic vessicle
• Can self replicate
• Involved in production and degradation of hydrogen peroxide

Network of filaments involved in cellular structure and motility

• Microtubules - rigid, hollow tubes made of aloha and beta tubulin
• Microfilaments - single filaments composed of actin

• Individual filaments are composed of beta and alpha tubulin. 13 filaments align along side one another and form a tube.
• Fxn: in flagella and cilia, in mitotic spindle

• Filament composed of action
• Fxn: squeeze membrane during phagocytosis and cytokinesis, provide contractile force in muscle contraction.

Axoneme: structure in cilia and flagella composed if 9 pairs of microtubules surrounding 2 individual microtubules in the center. Outer pairs of microtubules are connected with dynein protein. 9+2 arrangement (20 microtubules total)

Major MTOC in which the negative end of the microtubel begins and the positive end grows outward from during mieosis/mitosis

• 1. Tight Junction - water tight seal forming a barrier between cells (not the strongest junction)
• 2. Desmosome - like spot welds between cells, hold them together, but no barrier
• 3. Gap - tiny tunnels to allow ions and small molecules to move between cells

• Apical: surface facing lumen side of a cavity
• Basolateral: surface facing the base, or opposite of apical

• Role is to AcT as power house for cell - location of Krebs cycle
• Has own circular DNA coding for own RNA and ribosomes, self replicating
• No histones or nucleosomes
• Maternally passed

• 2 phospholipid bilayers
• Inner membrane forms cristae and is the location for electron transport chain
• Space between outer membrane and inner membrane is called inter membrane space

• To provide structural support, determine shape and motility, and affect cell growth.
• Surrounds cells
• Created by cell itself or fibroblasts

• 1. Neurotransmitter - nervous system
• 2. Local mediator - paracrine system
• 3. Hormone - endocrine system

• Neuronal - fast, specific/direct, and short distance
• Hormonal - slow, indirect/specific, long distance

Fluid between cells

• Brain, spinal cord, nerves, glia, special sense organs
• Fxn: allow rapid communication across the body for muscle and glandular activation/inactivation

• Cell specialized in communication via electricity and chemicals
• Do not divide
• All energy from glucose
• Do not need insulin for glucose uptake

Structure at the base of axon which hold the threshold limit

Signal - dendrite - axon hillock - axon terminal/ synapse

• Electrical gradient across the inside and outside of a cell membrane
• Sodium potassium pump, pumps out 3 sodium and 2 potassium in at a rate equivalent to spontaneous diffusion to maintain an equilibrium and potential

• Integral membrane proteins which change confirmation in response to voltage flux and allow ions into the cell
• Positive feedback/cascade

Polarity reversal when voltage gated sodium channels open

• Have a higher threshold for opening
• Open later than na channels and in response to depolarization
• Cause repolarization

• 1. Membrane at creating potential, sodium and potassium VGC are closed
• 2. Sodium Chanel opens - depolarization
• 3. Potassium channels open as sodium channels close
• 4. Sodium channels close and open potassium channels cause repolarization and hyperpolarization
• 5. Potassium channels close and membrane equillibrates through sodium potassium pump and passive diffussion

• Synapse: neuronal structure which propagates nerve impulses from one neuron to the next
• Electrical - uncommon, bidirectional, fast
• Chemical - common, unidirectional, slower, helps prevent fatigue

• 1. Over 50 different NT
• 2. 1 NT per synapse - will typically excite or inhibit
• 3. A single synapse cannot change between excitory and inhibitory
• 4. Some NT can excite or inhibit based on post synaptic receptor ie. Acetylcholine excites in smooth muscle, but inhibits in cardiac

• Ion channels
• Secondary messengera

White matter has myelin

Electrical signal jumping between nodes of ranvier as it propagates through an axon

• 1. Sensory ( afferent) - receive and transmit signals
• 2. Interneuron - transfer signals between neurons (most common)
• 3. Motor (efferent) - carry a signals to effectors (glands or muscle)

• Brain and spinal cord
• Fxn: integrate signals between sensory and motor

• Somatic - voluntary, external stimulus, skeletal muscle only (acetylcholine)
• Autonomic systems - involuntary (hypothalamus), internal stimulus, 2 parts
• sympathetic - fight/flight (epinephrine/norepinephrine)
• parasympathetic - rest/digest (acetylcholine)

• Lower brain: medulla, hypothalamus, thalamus, and cerebellum - unconscious stuff, pain and pleasure, neccessary for life
• Higher brain: cerbrum/cerebral cortex - stores memory and processes thoughts

Transduction of physical stimuli to electoral signal

Cornea - anterior cavity - lense (which is tensioned by the ciliary muscles) - vitreous humor - Retina - rods and cones (cones = color)

Iris: colored portion which gives shape to pupil

Outer ear - tympanal membrane - middle ear - 3 bones ( maleus, incus, stapes) - inner ear -cochlea - organ of corti - hair cells

Inner ear, function in balance and spacial orientation