Pathophysology chapter 1

Cellular functions

movement, conductivity, metabolic absorption, secretion, excretion, respiration, reproduction, communication

components of eukaryotic cell

cytoplasm/cytosol, intracellular organelles, plasma membrane

Cytoplasm function

synthesis and transport, isolates and eliminates wastes, metabolic processes, maintenance of cellular motility, storage of fats/carbohydrates/secretory vesicles

components of cytoplasm structure

cytoplasmic matrix, cytosol, and cytoplasmic organelles

Cytosol structure

gelatinous, semiliquid portion of cytoplasm

cytosol function

intermediary metabolism involving enzymatic biochemical reactions, ribosomal protein synthesis, storage of carbohydrates/fats/secretory vesicles

the function of histone

DNA supercoiling

Nucleus

contains genetic material and coordinates cellular activities

cells that contain more than one nuclei

hepatocytes, skeletal muscle cells, osteoclasts

Components of nucleus structure

nuclear envelope, nuclear pore complexes, nucleolus, RNA, DNA, histone proteins

Nuclear envelope

surrounded by cytoplasm, continuous with endoplasmic reticulum

nuclear pore complex

allow movement between nucleus and cytosol

Nucleolus

inner membrane of nuclear envelope, RNA, most cellular DNA, DNA binding proteins, and histones

RNA

transcription of DNA, synthesized in the nucleolus

DNA

genetic code

histone proteins

bind DNA/ allow for folding DNA

Nucleus function

cell division and control of genetic information, replication and repair of DNA

Transcription of DNA

Genetic information transcribed to RNA in the nucleus

Ribosomes structure

ribonucleic acid protein complexes

ribosome function

synthesize proteins

Newly formed ribosomes in the rough ER

synthesize a signal recognition sequence for mRNA and tRNA as well as formation of amino acids

Endoplasmic reticulum structure

network of tubular channels (rough has ribosomes attached)

Rough ER functions

packaging, folding proteins for secretion, lysosomal degradation, plasma membrane insertion, sending molecules to GA from modification

Smooth ER functions

reactions of toxic material and removal, communicates with Golgi complex, lysosomes, and peroxisomes, site of lipid steroid synthesis Ca++ storage in muscles, glycogen metabolism, detoxification in the liver

cisternae

flattened stacked membrane folds

Golgi apparatus structure

flattened, smooth membranes/sacs/cisterns, contains secretory vesicles and cisternae and clathrin-coated vesicles

Cis side of Golgi apparatus

receives proteins from rough er

trans side of golgi apparatus

releases vesicles toward plasma membrane

Golgi apparatus functions

processing, protein sorting, secretion, phosphorylation glycosylation and sulfonation of proteins lipids and hormones,

Lysosome functions

saclike structure that contains 60+ digestive enzymes (hydrolases)

How lysosomes maintain low pH

pumping H+ into interior to hydrolases can catalyze

lysosomes function

catalyze bond of proteins lipids nucleic acids and carbohydrates

Lysosomes digest

nutrients, intracellular debris, potentially harmful extracellular substances

Autophagy

A process in which lysosomes decompose damaged organelles to reuse their organic monomers

Primary lysosomes

contain inactive enzymes becomes activated when hydrolytic enzyme is activated when fused with vacuole or organelle

secondary lysosome

heterophagosome (activated form of primary lysosome)

Mitochondria structure

double membrane: outer is smooth and encloses organelle, inner had cristae which increase surface area, contains its own DNA

mitochondrial cristae

needed for aerobic respiration

mitochondria contain a transmembranous transport system to move

electrically charged Ca++ ions

Mitochondrial dna codes for

enyzmes needed fro oxidative phosphorylation

function of mitochondria

cellular respiration within inner membrane, participates in oxidative phosphorylation (ATP creation), metabolism of lipids, carbohydrates, amino acids, and special pathways for urea and heme synthesis

Peroxisomes structure

contain oxidative enzymes, larger than lysosomes, oval and irregular shape

the two organelles that use the most oxygen

mitochondria and peroxisomes

peroxisome function

detoxify compounds and fatty acids, use O2 to remove hydrogen atoms from specific substances producing H2O2

Peroxidase is a powerful \____ that is dangerous if it escapes the peroxisome

oxidant

Peroxidase decreased severity and catalyzes substances into

harmless products such as H20 and O2

Catalase - (Hydrogen + Radical) \=

Free Radical and Water

Cytoskeleton structure

protein filament network

cytoskeleton function

strength and support, movement of cellular structures and materials, movement of external projects (cilia, microvilli, flagella)

Mechanotransduction

conversion of mechanical stimulus to an electrical or chemical signal allowing cells to adapt to surroundings

Mechanotransduction plays a role in the pathology of \___ when disrupted or altered

hearing loss, heart disease, and cancer

Types of cytoskeleton

microfilaments, intermediate filaments, microtubules

Plasma membrane functions

enclose cell, selective transport system, cell-to-cell recognition, cellular mobility and shape

Microdomains of the plasma membrane

lipid rafts

cell membrane composition

semipermeable phospholipid bilayer made of lipids, proteins, carbohydrates, and cell receptors

phospholipid bilayer

An amphipathic double layer of phospholipids that makes up plasma and organelle membranes

How is the phospholipid bilayer amphipathic

head the face out are hydrophilic and polar, fatty tails which face inward are hydrophobic and nonpolar

Semipermeable membrane of cells

allows passage of certain molecules through (O2, CO2), denies passage of large molecules (proteins and glucose)

Types of membrane proteins

channels, carriers, pumps, enzymes

Glycoproteins

Membrane carbohydrates that are covalently bonded to proteins.

membrane proteins functions

transport, mobilization, gates transport, translocation, vesicular transport

types of membrane proteins

transporters, enzymes, surface markers, catalysts, CAMs

proteolytic cascade

breakdown of proteins by lysosomes

ubiquitin-proteasome system

ubiquitin proteins bind to molecules marked for degradation

Antiports

two substances in opposite directions

Uniports

one substance in one direction

symports

two substances move together in the same direction across the membrane by means of a single carrier protein

passive transport

the movement of substances across a cell membrane without the use of energy by the cell

facilitated diffusion

Movement of specific molecules across cell membranes through protein channels, typically with transport proteins or for bulkier molecules

active transport

the movement of materials through a cell membrane using energy

primary active transport

Active transport that relies directly on the hydrolysis of ATP.

secondary active transport

uses existing chemical gradients to move ions across membranes

Sodium-Potassium Pump

pumps 3 sodium ions out of the cell for every 2 potassium ions pumped in

receptor-mediated endocytosis

The movement of specific molecules into a cell by the inward budding of membranous vesicles containing proteins with receptor sites specific to the molecules being taken in; enables a cell to acquire bulk quantities of specific substances.

Exocytosis

Process by which a cell releases large amounts of material

Endocytosis

process by which a cell takes material into the cell by infolding of the cell membrane

how the membrane is repaired after exocytosis

lipids proteins and carbohydrates from the cell

types of receptor-mediated endocytosis

clathrin-mediated, caveolae-mediated, micropinocytosis, macropinocytosis, phagocytosis

hydrostatic pressure is greater than colloidal osmotic pressure in

arteries

colloidal osmotic pressure is greater than hydrostatic pressure in

vein

anaphylaxis

arteries widen from histamine and venous pressure drops

hypertonic solutions will

remove water from cells

hypotonic solutions will

allow water to enter cells

extracellular matrix

allows cells to form tissues and organs

types of molecules in extracellular matrix

adhesive, structural, proteoglycan, hyaluronic acid

adhesive molecules

integrins and cadherins which promote cell adhesion and cell anchorage

structural proteins

collagen, elastin, keratin, and fibroblasts give tensile and compressible strength

4 types of collagen

Type I - bone, skin, tendons

type 2 - cartilage, type 3 - reticulin, blood vessels, type 4 - basement membrane

Proteoglycans and hyaluronic acid

hydrates and cushions cells, improve cell communication, structure, and transport, only found between immobile cells

basal lamina

lies between epithelial cells and surrounds muscle fat and schwann cells

Cell adhesion molecules (CAMs)

surface proteins the bind cells together and to extracellular matrix

CAM protein families

integrins, cadherins, selecting, immunoglobulins

Integrins

receptors and regulate cell interactions with collagen, fibronectin, vitronectin and fibrogen

cadherins

calcium-dependent glycoproteins that hold similar cells together

Selectins

allow cells to adhere to carbohydrates on the surfaces of other cells and are most commonly used in the immune system

Direct cell to cell junctions

provide strong mechanical attachments, improve communication, structure and transport, create impermeable barriers

ways cells communicate

remote signaling, direct contact, gap junctions

autocrine signaling

Communication to same cell or neighboring cell of same type

paracrine signaling

signals nearby cells of different type

hormonal signaling

endocrine cells secrete hormone chemicals to produce response in other cells