Define organelle

organ of a cell; intracellular structures that do a specific function

Define Cell

basic structural and functional unit of living organisms

cell membrane (plasmalemma)

external boundary of cell; regulates flow of materials into and out of the cell; site of cell signaling

lysosomes

contains digestive enzymes of many varieties; "suicide sac" of the cell

mitochondria

scattered throughout the cell; major site of ATP synthesis

microvilli

slender extensions of the plasma membrane that increase its surface area

inclusions

stored glycogen granules, crystals, pigments and so on

Golgi body

"packaging plant" produces vesicle -> balls of membrane... produce lysomes & peroxisomes. membranous system consisting of flattened sacs and cesicles; packages protiens for export

nucleus

control center of the cell; necessary for cell division and cell life. "control center" of cell. contains chromosomes. - largest organelle. - usually near center of cell. - has double membrane, nuclear envelope. - membrane has openings, nuclear pores. - contains a dark spot -> nucleolus, ribosomes are produced. Typically 1 nucleus per cell

Exceptions to 1 nucleous per cell

1. red blood cells - annucleated 2. placental cell - binucleated 3. skeletal muscle cell - multinucleated

centrioles

pair of star shapped tubes. - Made of microtubules. - help separate chromatids during cell division. two rod-shaped bodies near the nucleus; associated with the formation of the mitotic spindle

nucleolus

"control center" of cell. contains chromosomes. - largest organelle. - usually near center of cell. - has double membrane, nuclear envelope. - membrane has openings, nuclear pores. - contains a dark spot -> nucleolus, ribosomes are produced. Typically 1 nucleus per cell

microfilaments

contractile elements of the cytoskeleton

endoplasmic reticulum

membranous system; involved in intracellular transport of proteins and synthesis of membrane lipids

ribosomes

translation process of protien synthesis - chromosomes have genes that code for protiens -> used to express genes. Attached to membrane systems or scattered in the cytoplasm; site of protein synthesis

chromatin

threadlike structures in the nucleus; contain genetic material (DNA)

peroxisomes

site of free radical detoxification

significance of the red blood cell being anucleate

they cannot reproduce & have infinite life span

did anucleate red blood cells ever have a nucleous

Yes - during development

what is the importance of cell division

allows for growth and repair

division of the _____ is refered to as mitosis

nucleus

cytokinesis is division of the ____

cytoplasm/ organelles

the major structural difference between chromatin and chromosomes is tht the latter are _____

duplicated & condensed

Chromosomes attached to the spindle fibers by undivided structures called _____

centromere

if a cell undergoes mitosis but not cytokinesis, the product is

binucleated cell

the structure that acts as a scaffolding for chromosomal attachment and movement is called the

spindle fibers

_____ is the period of cell life when the cell is not involved in division

interphase

two cell populations in the body that do not routinely undergo cell division are ___ & ___

Skeletal muscle & neurons

chromatin coils and condenses, forming chromosomes.

prophase

the chromosomes are V shaped

anaphase

the nuclear envelope re-forms

teleophase

chromosomes stop moving towards the poles

teleophase (late anaphase)

chromosomes line up in the center of the cell

metaphase

the nuclear envelope fragments

prophase

the mitotic spindle forms

prophase

DNA synthesis occurs

interphase

Centrioles replicate

interphase

chromosomes first appear to be duplex structures

prophase

chromosomal centrometers are attached to the kinetochore fibers

metaphase (late prophase)

chleavage furrow forms

anaphase

the nuclear envelope is absent

metaphase & anaphase

what is the physical advantage of the chromatin coiling and condensing to form short chromosomes at the onset of mitosis?

easier to move the separate daughter chromosomes to he newly forming cells.

cell membrane - purpose & structure

purpose - defines boundary of cell
keeps all alive by controlling what can and cannot get in and out

protiens - 2 types

integral - go through membrane
peripheral - on 1 side only

protiens uses

-channels/pores - intake nutrients - carriers/ transporters - receptor-input - cytoskeleton anchor (shape) - enzymes - cell identity markers - cell connectors - fluid mosaic membrane

carbohydrates

blood type

cholesterol

- cell movements across membrane.

What are passive movements

molecules spread through the membranes. Molecules move from an area of high concentration to an area of low concentration, down a concentration gradients. As molecules diffuse, a state of equilibrium will occur - simple diffusion. - channel mediated diffusion. - carrier mediated diffusion. - osmosis. - dialysis. - filtration.

passive movements - simple diffusion

- move directly through phosipolipids. - move from high concentration to low concentration via driving force. - things that can do this are fat soluable... ie. h20, 02, co2, n2, steroids

Passive movements - channel medinated diffusion

- requires channel/pore. - membrane has negative charge. (cations would get stuck/anions would repel)

Passive movements - carrier mediated diffusion

- requires a carrier. - modify substance after it crosses... ie. glucose turns to glucose 6 phosphate. ATP + Glucose -> ADP + glucose 6 phosphate

Passive movements - Osmosis

diffusion of water driven by solute concentration (solute-protein, sugar, salt)

passive movements - osmosis - hypertonic

*Osmosis* net water movement out, cell shrinks

passive movements - osmosis - hypotonic

*Osmosis* net water movement in, cell expands - lysis explodes

passive movements - isotonic

* no osmosis* same concentration - no water movement

passive movement - dialysis

* Osmosis * passive through membrane based on pore size - peritoneum dialysis - shunt tube - blood vessels - in abdominal cavity - as blood flows through blood vessels & filter through poresin capilaries

passive movement - dialyisis - filtration

* Osmosis* in kidney - movement across a membrane due to pressure difference.

Active methods & types

1 - pumping a. requires ATP * carrier molecule required * Moving opposite of concentration (lower to higher) * Na/K pump 2. a.

Membrane "Shape" Organs - types

Endocytosis * Exocytosis

active transport - endocytosis

moves substances into the cell by means of a vesicle.

active transport - endocytosis - phagocytosis

cell eating. large particles are engulfed by plasma membrane and enter the vesicle - the vesicles fuse with lysosomes, which digest the particles

active transport - endocytosis - pinocytosis

cell drinking. fluid and the substances dissolved in it enter the cell

Active transport - Endocytosis - receptor mediated

receptor molecules recognize substances to be brought into the cell

Active transport - Exocytosis

movement out of the cell - contains secretory vesicle - neurotransmitters & some hormones released this way. large molecules (proteins) can leave the cell even though they are too big - enclosed in vesicle then pulled to plasma membrane via cytoskeleton.

Role of active transport processes

a. active transport requires energy use by the membrane b. pumps - concrentrate substances on one side of membrane, as when stroing an ion inside of an organelle c. vesicle-mediated (endocytosis, exocytosis) - move large volumes of substances at once, as in secretion of hormones and neurotransmitters

cell - cell connections

a. tight junctions - prevents movement between cell b. desmosomes - connection that allow movement together c. gap juncions have tubes(connections) that allow direct cell to cell communication ie. heart

cell membrane modifications

1. microvilli 2. cilia 3. flagellium

cell membrane modifications - microvilli

extensions that increase the cells of surface area

cell membrane modifications - cilia

hair like structure - beat = move substances over their surface ie lungs and fallopian tube

cell membrane modifications - flagellium

long, whip like tail ->provides mobility ie. sperm tail

Ribosome process

DNA(code) -> RNA(Copy) -> Protien ribosome translate the RNA codes. Ribosomes are formed in nucleus

DNA process

Chromatin -> Chromosomes -> Chromotids. DNA = genetic code. stands for Deoxyribonucleic Acid. 2 strands of nucleotides twisted around each other in a double helix. Each side consists of sugar & phosphate. Runs - base pairs

DNA - T

thymine

DNA - A

Adenine

DNA - C

Cytosine

DNA - G

Guanine

Chromotin

DNA wraps around protein beads called histones. Form loose, tangled strains, normal form in cell

Chromosomes

formed in division. X shaped structures. condensed duplicated chromotin. human cells have 23 pairs & 46 chromosomes. xy = men. xx = woman

centromere

middle, central part of chromosome

chromatid

half of the chromosome after it divides - also called sister chromatids (daughter chromosomes)

Cell life cycle - 4 phases

G1 - growth - normal cell function. S phase - Synthesis - DNA replicates, centride replication. G2 - growth 2 - normal activity - final preparations for division. M - Mitosic - division of nucleous, cytoplasm & organelles.

Metabolism

set of chemical reactions in a cell. Catabolism & Anabolism

anabolism

build up reactions. creates A+B -> AB + H20

catabolism

breaksdown reactions. AB + Hw0 -> A+B - hydrolysis, digestion, food (cellular respiration pathways) -> ATP

mitotic cell division - Mitosis is?

Cell Division process - makes exact copies of cell for growth and repair

mitotic cell division - Mitotic base pairing - 5 phases of Mitosis

IPMAT - Interphase, Prophase, Metaphase, anaphase, telophase

mitotic cell division - Interphase - G, S, & G2

DNA synthesis - production of cytoplasm - replication of centrosomes and DNA in anticipation of cell division

mitotic cell division - Interphase - DNA Synthesis - Base Pairing

DNA strand uncoils and strands come apart - strands are rebuilt in opposite directions, 1 strand strand that has telomeres. Telomers are segments at the end of DNA, that rebuild by the enzyme telomerase. T=A A=T G=C C=G -> will always be prepaired together, on opposite sides. 2 new strands are chromatids

mitotic cell division - Prophase

"before phase" 1. chromatin condenses to chromosomes 2. nuclear membrane disappears 3. nucleoi disappear 4. centrioles begin to move to opposite ends, spidle fibers form between them

mitotic cell division - Metaphase

"position changing phase" 1. chromosomes attach to spindle fibers 2. chromosomes align to the middle of cell

mitotic cell division - anaphase

"apart phase" 1. chromosomes split into chromatids 2. chromatids pulled to cellic pole by centrioles & spindle fibers. centromere of each chromosome splits to form 2 chromosomes, each consisting of a single DNA molecule 4. each chromosome is pulled toward the nearest pole to form 2 separate, but identical, pools of genetic information

mitotic cell division - telophase

"end phase" 1. division of cell membrane -> furrowing 2. cytokinesis -> division of cytoplasm/organelles 3. chromatid becomes chromotin 4. nuclear membrane reforms 5. nucleoli reappear 6. each daughter cells begin interphase to develop into mature cell

summary of Mitosis

1. DNA replication 2. 1 round of division 3. forms 2 identicle cells (daughter cells)

Why do cells divide

1. get too big - problems surface area to volume. 2. growth factors, a. HGH - human growth hormone b. PDGF - platelet derived growth factor. 3. cyclic factors

What stops division

1. removal of growth factors 2. removal of cyclic factors 3. contact inhibition 4. natural killer (NK) cells 5. Tumor suppressor Gene (TSG) protiens

Cancer

uncontrolled cell growth -> crowd out healthy tissue, impair normal function cells change methology, cancer can spread

Causes of Cancer

1. carcinogens 2. Radiation 3. Oncogenes 4. loss of TSG 5. NK cell problems 6. Age 7. Virus infection -> that have oncogenes themselves