membrane bound

intracellular digestion

turnover of cell components

contains hydrolytic enzymes

membrane resistant to enzymes

degrade macromolecules from endocytotic pathways and atophagy

in some cells hydrolytic enzymes can be excreted

removal of organelles

performed by the lysosome

synthesized in the RER

the enzymes are packaged in the golgi complex

caused by defective enzymes

result in accumulation of substrates that were suposed to be used in enzyme reactions

there are 49 total, know tay-sacs and gaucher

children appear normal at birth but have slow growth, changes in facial features, bone and joint deformities, loose skills, mental retardation, lung infections, heart disease, enlargement of organs (hepatosplenomegaly)

enlargement of the spleen and liver

occurs in lysosome storage diseases

lysosomal storage diseases

deficiency of beta-hexosaminidase which causes gangliosides in the CNS to accumulate filling the neuron and killing it

The most prodominate symptom is the cherry red spot in the eye

lysosomal storage disease

defective glucocerebrosidase causing accumulation of glucocerebrocides in the spleen, liver, and CNS

can be treated with enzyme replacement therapy

has 2 subunits composed of 4 types of RNA with 80 different proteins

RNA is made in the nucleus for both subunits and leave via nuclear pores

translate mRNA in protein synthesis

can be held together by strands of mRNA forming polyribosomes

membrane with interconnected sacs and channels that enclose the cisterna space

two types: rough and smooth

involved in steroid metabolism

glycogen metabolism

membrane formation and recycling

detoxification and conjugation of noxious substances

specialized smooth endoplasmic reticulum only in muscle cells

sequesters calcium

complete post translational modifications, package, and place an address on products made in the cell

made of smooth membrane limited cisternae that look like flat sacs

the cis or forming face recieves molecules made by the RER, processes them, and releases them from the trans face in larger vesicles that have secretory granules, lysosomes, or other cytoplasmic components in them

aka inclusion cell disease

rare, inherited

poor growth and mental retardation

caused by deficiency of phosphotransferase, a phosphorlating enzyme, in the golgi

when not phosphorlated, proteins are not seperated to form lysosomes and the lysosome is empty causing a build up of inclusion granules that interfere with metabolism

transforms chemical energy of metabolites into energy for the cell via the citric acid and cell cycle; 50% is stored as ATP, 50% dissipates as body temperature

has a double membrane and circular DNA strand

contains ATP synthase in the membrane which has folds called cristae

mitochondria is only inherited from the mother

male and female can be affected but males are more often affected and luckly cannot transfer the disorder

know MERRF, LHON, male infertility, pearson marrow-pancreas syndrome

mitochondrial disease

myocolnic epilepsy with ragged red fibers

muscle weakness, loss of cordination (ataxia), seizures

cardiac arrest and respitory failure occur due to degredation of respitory muscles

red muscle fibers appear ragged due to aggregations of mitochondria

mitochondrial disease

Leber's hereditary optic neuropathy

85% male affected

confined to the eye

sudden loss of vision in 20s or 30s

mitochondria disease

anemia and mitochondrial myopathy observed in childhood

spherical organelle

oxidize specific substances by removing H+ and transferring them to O producing hydrogen peroxide

catalase breaks down hydrogen peroxide and is also in the peroxisome

it also has d-amino acid oxidases and beta-oxidation enzymes involved

in the liver

detoxify aocohol by converting it to acetaldehyde

(fyi they are also abundent in the kidney)

number of peroxisomes can increase de to diet, drugs, hormones

most commonly inherited peroxosomal disease

rare, congenital, leathal in first year of life

is a leukodystrophy disease

reduction of absence of peroxisomes in hepatocytes, kidney, and brain

caused by PXRI mutation so receptors on the peroxisome dont recognise

network of microtubules (move organelles), actin (microfilaments), and intermediate filaments

maintains cell shape, moves organelles and vesicles, moves cells

immobilize cillia: mucus cannot be cleared causing infections, sperm motility of compormised, lack of cillia in the uterine tubes can cause infertility

may cause side reversal of organs, situs intersus' when there is kartagber's sundrome

membrane limited compartment that contains the genome

contents: chromatin, nucleolus, nuclear envelope (dual membrane), nucleoplasm

complex of DNA and proteins (the proteins keep the DNA organized)

in non dividing cells it is coiled or condensated to varying degrees

two types: heterochromatin, eucromatin

more condensed form of chromatin

more coiling makes it darker when dyed

electron microscope: coarse electron dense granules

light microscope: basophillic clumps

less condensed form of chromatin

contains parts of DNA that the cell is currently using because it needs to be more accessable

electron microscope: finley dispersed granular material

light microscope: lightly stained basophilic areas

basic structural unit of chromatin

2 loops of DNA wrapped around a core of 8 histones linking a 2nm filament of DNA like beads on a string

can form a chromatin fibril

30nm long

nucleosomes coiled around an exiz

six nucleosomes per turn

23 homologous pairs (22 are autosome pairs, 1 pair of sex chromosomes)

XX female, XY male

46 chromosomes is the diploid number (2n)

can be studied by examining in methphase

chromosomes are sorted by size shape and staning pattern

reveals abnormal chromosome numbers or structures

aka barr body

heterochromatin mass observed in female cells but not male cells

represents a tightly coiled X chromosome

visible as a small granule attached to the nuclear envelope of epithelial cells looking like a drumbstick appendage to the nucleus of neutrophilic leukocytes

side of rRNA synthesis and initial ribosome assembly

non-membranous

vary in size

can have more than one per cell

region of the nucleolus

contain DNA loops of chromosomes containing rRNA genes

region of the nucleolus

rRNA genes being actively transcribed

large amounts of rRNA

region of the nucleolus

densleu packed peribosomal particles

seperates the nuclear compartment from the cytoplasm

has two membranes with a cisternal space between them

has nuclear pores that regulate passage through the membrane

resembles and is continoous with RER membrane

may have ribosomes on the cytoplasmic surface

supported by the nuclear lamina

contains receptors that bind the lamina and chromosomes

netowork of protein filaments

provides support

organizes chromatin, chromatin associated proteins, nuclear pores, and membranes of the nuclear envelope

associated with the inner face of the nuclear envelope

70-80nm openings formed by the merging of the inner and outer nuclear membrane

each contains a nuclear pore complex

made of proteins that mediate transport in and out of the nucleus

has a GTP dependent mechanism for large proteins and complexes

water molecules may cross water filled channels by diffusion

small proteins are selectivly transported

material enclosed by the nuclear envelope exclusive of the chromatin and nucleolus

nucleoskeleton, nuclear lamina, RNA transcription and processing machines

self regulated sequence that controlls cell growth and division

principal phases: interphase and m phase

growth of the cell

divided into G1, S, G2

part of cell cycle interphase

gathers nutrients

synthesis of RNA and proteins

restore cell volume

has 2 check points

restriction point: most important, point of no return. mediated by retinoblastoma susceptibility protein (pRb) and essential transcription factors (E2F)

G1 DNA Damage check: tumor supressing protein p53 mediates, high p53 will arrest cell cycle

it can leave the cycle and enter G0 or under go programmed cell death

if it goes wrong a tumor may develop

if it happens in M you can get mitotic catstrophe or restriction point failure leads to loss of contact inhibition

part of cell cycle interphase

DNA is replicated

contains DNA damage check point (same type as G1)

part of cell cycle interphase

accumulation of energy

tubulin synthesis

synthesis of chromosomal nonhistone proteins

DNA damage check (same type as G1)

unreplicated DNA check point

part of cell cycle

mitosis: karyokinesis, cytokinesis

contains spindle assembly checkpoint and chromosome segregation checkpoint

the proteins are cyclically synthesized and degraded

two protein complexes made of cyclin and a cyclin dependent kinase power cells through checkpoints

process of nuclear and cellular division

produces two daughter cells with chromosomes identical to the parent

has 4 phases

prophase

metaphase

anaphase

telophase (and cytokinesis)

chromosomes condense and become visible

sister chromatids are hed together by cohesins and the centromere

centrosomes migrate to poles

nucleolus dissipears

mitotic spindles form

kinetochore forms on each chromatid

nuclear envelope dissassembles

chromosomes migrate to the equatorial plane

mitotic spindles organize around the microtubule organizing centers

microtubules attach at kenatochores

nuclear envelope is reconstituted in each new cell

chromosomes uncoil

nucleolus reappears

cytokinesis occurs

two sequential cell divisions that make gametes containing half the number of chromosomes and half the DNA in somatic cells

creates genetic diversity due to combination of paternal and maternal chromosomes and crossing over

there is no S phase between the set of divisions

S phase

meiosis starts: 2n

after meiosis 1: 1n

after meiosis 2: 1n

extended phase of 5 stages: leptotene, zygotene, pachytene, diplotene, diakinesis

overall pairing synapsis and recombination occurs

prophase 1 stage 1

chromatin condensation and pairing of homolorous chromosomes

prophase 1 stage 2

synapsis, formation of the synaptonemal complex

prophase 1 stage 3

crossing over

prophase 1 stage 4

synaptonemal complex dissolves

chromosomes condense further

chiasmata appear

prophase 1 stage 5

maximum chromosome condensation

nucleolus dissipears

nuclear envelope disintegrates

paired chromosomes align at equatorial plate

chiasmata breakdown

centromere does not split

sister chromatids stay together

members of each homologous pair move to poles in a random assortment

nuclear envelope reforms

cytoplasm divides

produces daughter cells that are 1n

basically mitosis

a 1n cell becomes two 1n daughter cells that are not genetically identical

can result from accidential injury or mechanisms that initiate it

types: necrosis or apoptosis

accidential cell death

pathalogical processes

unfavorable physical or chemical enivorment

characterized by rapid cell swelling and lysis

programmed cell death

physiological process, cells not needed are elimiated

initiated and programmed internally

rapid process

irreversable

chromatin aggregate

nucleus may fragment

cytoskeleton reorganizes

ribosomes clump

RER forms whorls

endocytotic vesicles fuse with plasma membrane

change in membrane permability

electron transport chan disrupted

cytochrome C is released into the cytoplasm activating capases which dismantle the cell

plasma membrane alterations

leads to blebbing without loss of integrity

cell breaks into membrane bound vesicles rapidly removed by phygocytic cells

no inflamatory response is elicited

contains organelles and inclusions

has cytoplasmic matrix

can be membrane and non membrane bound

located in the cytoplasm

spaces inside are intracellular micro compartments

structures or substances not surrounded by plasma membrane in the cytoplasm

can be crystals, pigment granules, lipids, glycogen, or waste

membranouns organelle

selectivly permable

 modified fluid filled mosaic model

made of cholesterol, phospholipids in a bilayer, proteins (half of the mass)

proteins embedded in the plasma membrane spaning it completely

can be visualised using freeze fracture

function in cell metabolism, regulation, and integration

there are 6 categories that are not mutually exclusive

aka cell coat

surface molecules, glycoproteins and glycolipids, that make up a layer on the plasma membrane surface

functions in metabolism, cell recognition, cell interaction, and receptors

part of the plasma membrane glycolax

carbohydrates attached to the proteins of the extracellular surface

part of the plasma membrane glycolax

carbohydrates attached to lipids of the membrane

microdomains of the plasma membrane control movement and distribution of proteins within the bilayer

have high concentrations of cholesterol and glycosphingolipids

thick, less fluid due to the cholesterol and long chain fatty acids

have integral and peripherial proteins for cell signaling including receptors, coupling factors, effector enzymes, and substrates

signal transmission occurs rapidly due to close proximity of interacting proteins

when preparing for electron microscopy the membrane splits creating an E and P face

the E is backed by extracellular space

the P (aka protoplasm) is backed by the cytoplasm. this face has more particles

category of integral protein

transports ions like Na across the membrane as well as macroprecursors

category of integral protein

type of membrane transport

allow passage of small ions, water soluble molecules, and water across the membrane in both directions

ex: gap junction

create hydrophillic channels to regulate transport

three types of gates for regulation

category of integral protein

allow recognition and localized binding of ligands in hormal stimulation, cated vesicle endocytosis, and antibody reactions

category of integral protein

anchor intracellular cytoskeleton to the extracellular matrix

ex: integrins link cytoplasmic actin to extracellular matrix protein fibronectin

category of integral protein

include ATPases involved in ion pumping, ATPase synthase in mitochondrial membrane, and digestive enzymes like dipeptidases and disaccharidases

category of integral protein

visualized by freeze fracture especially where they form junctions with other cells

simple diffusion

carrier proteins

channel proteins

vesicular

pinocytosis

phagocytosis

type of membrane transport

allows fat soluble and small uncharged molecules across the membrane

voltage gated: regulated by membrane potential ex: neurons

ligand gated: neurotransmitters ex: ach receptors in muscle

mechanical gated: triggered by physical stress ex: inner ear

type of membrane transport

transfer small, water soluble molecules

very selective

it binds to the molecule, changes conformation, then releases it on the other side of the membrane

some carriers, like the Na/K pump, require energy to pump against a concentration gradient (active transport)

some carriers, like the glucose carriers, do not need energy (passive transport)

maintains integrity of the plasma membrane

configurational changes in the membrane at localized sites near formation of vesicles or fusion

types: endocytosis and exocytosis

type of vesicular transport

brings large substances into the cell

can be mediated by receptors

ligand binds to cell receptor

receptor aggregates into a coated pit for the substance

pit invaginates into the cell

coated vesicle fuses with endosomes (vesicles and tubules in the cytosol)

low pH in endosomes seperates ligand and receptor

ligand oes to the lysosome, receptor is returned to the cell membrane

small invaginations in the membrane trap extracellular fluid and any molecules it in

cell drinking

cell eating

cells like macrophages and polymoorphonuclear leukocytes are specialized for engulfing and removing bacteria, protozoa, fungi, damaged cells, and trash