ch 3 patho exam 1

small, simple cells with no defined nucleus or organelles

cell membrane

proteins embedded in the plasma membrane that do most of its functions

has a polar end attracted to water and another repelled by water

to eliminate contact of the hydrophobic tails with water

cholesterol, phospholipids, and glycolipids

extend across the membrane bilayer and are in contact with ECF and ICF

transport, transduction of EC signals into IC messages

connect neighboring cells and function to confine proteins to an area of the membran

have organelles with membranes and specific functions

cytoskeleton

actin, microtubules, and intermediate filaments

• actin
• muscle

originate at cell center / centrosome & radiate out to cell perimeter

guide orderly transport of organelles and visicles in cytoplasm & equally distrubute chromosomes during cell division

The inner membrane goes all the way around the nucleus and has binding sites for proteins that organize the chromosomes inside.  The outer membrane is continuous with the ER and resembles it in structure and function

the nuclear pores are selective about what is allowed into the nucleus

synthesis of membrane components (proteins, lipids) & products to be secreted from the cell

coated with ribosomes

complexes of protein & RNA from the nucleus that synthesize proteins

signal recognition particles

special proteins that bind to sequence of codons that direct the ribosomee responsible for its synthesis

lipid metabolism & Ca storage

liver cells - produce lipoproteins & detoxify harmful lipid soluble substances (alcohol)

muscle cells - stores Ca and releases it when stim for muscle contractions

receives proteins by way of ER transport vesicles -> modified by enzymes that attach or rearrange carb molecues -> put in golgi complex transport vesicles -> pm, lysosome, or other area needed

cell becomes smaller and more energy efficient

• lysosomes
• autophagy

what is formed when a WBC ingests particles

They fuse with a lysosome

simple molecules - AA, fatty acids, and carbs that can be used by cell or secreted as cellular waste

inclusion cell disease - lack the enzyme mannose -6-phosphate that attaches a marker to send enzymes to the lysosomes and sends them outside the cell instead - lysosomes have no enzymes and cannot function

microbodies

bags of enzymes that perform degradative functions

liver and kidney cells where they detoxify various substances

lysosomes contain hydrolase enzymes and peroxisomes contain oxidative enzymes that produce hydrogen peroxide & peroxisomes aquire enzymes from cytoplasm instead of golgi complex

used by enzyme catalase to degrade toher organic molecules

• 1. degrade other organic molecules
• 2. prevent accumulation of excess hydrogen peroxide by converting it to water and O2
• 3. oxidize fatty acids to produce acetyl coenzyme A used in cellular metabolism

mitochondria

cariac or skeletal muscle cells

phosphate bonds are broken by hydrolysis(with water) and release energy (approx 11-13 kcal)

enzymes use the energy to break or make other chemical bonds

ATP cannot cross the plasma membrane

breakdown of glycogen and fat

protein

gluconeogenesis

anabolism and catabolism

anabolism - synthesis of complex molecules such as fat that uses energy

catabolism - breakdown of nutrient sources that releases energy/ATP for use

• 1. absorption of simple molecules by the small intestine
• 2. glycolysis
• 3. citric acid cycle
• 4. oxidative phosphorylation

anaerobic process that produces 2 AT, 2 NADH, & 2 pyruvate molecules per glucose molecule used

anaerobic and used in reduced cellular oxygenation - resp, and cardiac probs

dangerous condition with excess lactate in blood stream due to severe or prolonged lack of oxygen

during glycolysis pyruvate is released and excess is converted to lactic acid and released into the bloodstream

pyruvate enters mitochondria and is converted to acetyl CoA with release of CO2 molecule

glycolysis

red blood cells

break by oxidation the C-C & C-H bonds of compounds produced in glycolysis

pyruvate and fatty acids enter mitochondria from glycolysis -> converted to acetyl CoA -> 1CO2, 1NADH & 1 acetyl CoA formed by cleaving of pyruvate & 1 NADH & 1 FADH2 formed by cleaving of fatty acids

acetyl groups supplied by acetyl CoA are oxidized to form a lot of H- (hydride ions) that are carried to the respiratory chan by NADH AND FADH2

in the mitochondrial matrix

2 GTP, 4 CO2, 2 FADH2, & 6 NADH

NAD & FAD that are reduced by H- in the citric acid cycle to NADH & FADH

H- gives energy for the electron transport chain in mitochondira & NADH & FADH are carrier molecules that bring the H- to the mitochondria

at the end of the transport chain O2 is needed to form H20

redox

transport electrons and from a proton (H+) gradient that provides energy for ATP synthesis

ATP synthase

• 30
• 2
• 2
• 26

ATP synthase

ATP synthase captures the energy of th epoton gradient and uses it to form a bond b/t ADP and inorganic phosphate

cellular ingestion of ECF molecules in vesicles

pinocytosis- ingesting fluids & small particles

phagocytosis - ingestion of large particles 

large molecules cannot pass through trasport proteins and must be transported through vesicles

cellular secretion from vesicles

receptors regulate what comes in cell and how much of it

more receptors can be added or taken away to regulate intake of specific molecules

histamine

exocytosis

transporter proteins

ATP driven pumps, carriers, & channel proteins

water pores in the PM that allow certain size and charge water-soluble membranes into the cell

bind to them and transport them through

active and passive

ions diffuse pasively b/cof electrochemical gradient due to differences in ICF and ECF charge and/or conc gradients

transport protein uses flow of other molecules down gradient to move another substance uphill against its gradient

channels called aquaportins

osmosis

protein transport pumps move solutes across the membrane against an electrochemical or concentration gradient

moves 3 Na out and 2 K in for every pump

maintain cell volume by controlling osmosis, secondary active transport

• low
• PM & ER

Ca pumps pump Ca into mitochondria using energy from the proton gradient used in ATP production

ATP production is inhibited b/c Ca is using its pathway - this is dangerous to the cell

bacteria use ABC transporters to pump antibiotics out of the cell

Na gradient created by Na K pum is used to power secondary active transport of other molecules

Na tranports Ca out of cardiac muscle cells (decreases contraction), takes H+ out to control pH, transports glucose and AA into epi cellsreuptake of neurotransmitters from synapses

always present in PM and let substances in based on their concentration in the ECF

Bcells of pancreas detect blood glucose transport glucose based on its conc in ECF, & release insulin

releases insulin in response to blood glucose level that goes to other cells that take up glucose and enters glucose carriers -> transported into cell -> lower blood glucose

selective proteins that form water-filled pores in the membrane and allow specific  ions to flow through by simple diffusion

• 1. voltage gated
• 2. mechanical gated
• . ligand-gated

respond to change in membrane potential

respond to mechanical deformation

respond to the binding of a signaling molecule/hormone/neurotransmitter to a receptro in the cell surface

responsible for membrane potentials

resting membrane potential - electrical charge present inside the cell when no net ion movement across the PM

differnce in K across the membrane

30 X greater in ICF

• K
• Na & Ca

attraction of fixed ICF anions pulls K (Na & Ca are not permeable) in -> as K conc increases in ICF the conc gradient of K favors K moving back out of cell =processes balance out when cell at rest

electrical exceitatios of the membrane that are mediated by ion channels that open and close in response to changes in voltage across the membrane

by membrane depolarization

neurotransmitter binds to cell surface receptor -> channels in membrane open and allow Na to enter the cell & K to leave the cell -> threshold is reached when a section of membrane is suffiiciently deplarized to activate voltage-gated Na channels in the membrane -> open and allow more Na ions in -> ongoing chain more Na = more Na gates opening

Na inflow is stopped by closing Na channels & k outflow through K channels decreases

Ca is allowed into the cells during repolarization and prolongs action potential allowing contraction to finish before another impules is conducted

• 1. gap junctions - directly connect the cytoplasm of adjoining cells
• 2. direct cell-to-cell contact of PM or ECF molecules ass with the cell
• 3. secretion of chmical mediators (ligands) that influence cells some ditance away

small molecules can - ions, glucose, aa, nucleotides, and vitamins

large molecules cannot - molecules formed by many of the small molecules together (protein, nucleic acids)

occurs only in cells of the NS, & occurs at synapses small distances apart

neuron secretes a chem neurotransmitter into the synapse of the nerve and the target cell -> NT diffuses cross synaptic cleft and binds receptors on postsynaptic cell

chemicals secreted into a localized area and are rapidly destroyed so that only cells in the imm area are affected

specialized endocrine cells secrete hormones that ravel via the bloodstream to target cells widly distributed in body

cells are able to respond to signaling molecules that they secrete

they have specific protein receptors for that ligand

• receptors
• internal structures

most are water soluble

bind NT, causing specific ion channels in the membrane to open or close

catalyze enzyme reactions when they are activated by appropriate ligands

act indirectly througha membrane-bound trimeric g-protein that binds to GTP when activated by the receptor-> influences activity of specific enzymes -> produce 2nd messengers that cause a cascade to change the cell function

some lipid soluble hormones pass through PM and interact with receptors inside the cell

• 1. protein mitogens and growth factors are required in specific combos for growth and proliferation
• 2. cells respond to spatial signals from ECF & neighboring cells that indicate how much room is available