cell communication and cell cycle

all multicellular organisms must ________ to maintain homeostasis

communicate and cooperate

occurs when a cell targets itself

autocrine

membranes that are touching have membrane proteins that help with communication

cell to cell (juxtacrine)

communication of molecules, creates response in other cells

short distance (paracrine)

cell secretes signaling molecules to nearby cells

paracrine

stimulation of nerve cells by neurotransmitters

synaptic

longer distance or larger number of cells

long distance (endocrine)

chemical molecules that bond with proteins. Can’t pass through membrane

ligand

membrane protein that bonds with ligands

receptor

internal proteins that relay message

secondary messangers

signal transduction: the ligand bonds to the specific receptor protein which will change its shape

stage 1: reception

signal transduction: reception sets off a relay team of communication proteins in the cell; second messengers carry the original exterior signal to the inside of the cell

stage 2: transduction

signal transduction: the cell will respond to the signal as directed (ex: make a protein, produce more energy, enter mitosis, etc.)

stage 3: response

shows molecules that is being activated or moved

arrows

shows molecule that is being inhibited

bar headed lines

transfers (adds) phosphate groups from ATP to other molecules

kinases

remove phosphate groups from proteins

phosphatases

series of kinases add a phosphate to the next one in line, activating it, and sending the signal to the target, like a bucket brigade

phosphorylation cascade

receptor protein binds with ligand, G-protein becomes active by changing GDP to GTP, G-proteins activates other proteins

G protein receptor

when ligand binds with the receptor, receptor acts as a gate and opens, allowing ions through

ligand-gated ion channel

ligand binds with receptor, tyrosines come together and form dimers, internal phosphorylation activates responses

receptor tyrosine kinases

small or hydrophobic chemical messengers pass through membrane easily

intracellular receptors

ligand bonds with protein within the cell. Activates DNA to produce a protein

intracellular receptor

product of a reaction leads to an increase in that reaction. Stimulus is increased by product. maintains homeostasis

positive feedback

product returns condition back to its stable target point

negative feedback

tightly packed DNA and protein structure

chromosome

protein molecule that DNA wraps itself around

Histone

thin thread of DNA. condenses before mitosis. Consists of DNA and histones

chromatin

arm of chromosome (half a chromosome)

chromatid

sister chromatics are attatched at region with many DNA repeats

centromere

identical DNA stands that remain attatched until mitosis

sister chromatids

homologous chromosome

pair of chromosomes with identical features

homologous chromosome

pair of chromosomes with identical features

how many PAIRS of chromosomes does a person have

23

what sets of chromosomes are autosomes (same for all)

1-22

what pair of chromosomes are the sex pair

23

number of average chromosomes in a somatic cell. Includes two chromosomes of each kind

diploid (2n)

cells that contain only one of each chromosomes, like sperm and egg

haploid (n)

produces 2 diploid cells, occurs in skin cells

mitosis

produces 4 haploid cells, occurs in egg cells and sperm cells

meiosis

cell grows in size, increases number of organelles (what phase)

G1

DNA replication (what phase)

S

protein synthesis, division prep (what phase)

G2

set of stages that take place when a cell divides

cell cycle

what part of the cell cycle is the longest

interphase

“Lazy phase” cell continues normal functions, doesn’t divide.

G0

organelle that aids in cell division. Made of Centriole and microtubules

centrosome

barrel shaped organelles, organizes and produces spindle fibers

centrioles

responsible for moving chromosomes around cell during mitosis

spindle fibers

regions on the centromere where spindle fibers will attach

kinetochores

nuclear division

mitosis

division of cytoplasm

cytokinesis

chromatin condenses into chromosomes, nuclear envelope breaks down, nucleolus disappears, spindle fibers form, centrioles migrate to opposite sides of cell

prophase

chromosomes line up in the middle of the cell, spindle fibers attach to chromosomes at the centromere

metaphase

sister chromatids separate and are pulled to opposite ends of the cell, cell becomes oval

anaphase

spindle fibers disappear, two new nuclear envelopes appear, two new nucleoli are formed, chromosomes relax back into chromatin

telophase

starts during telophase, division of the cytoplasm, seperation into two cells

cytokinesis

cell membrane pinches in the middle, microfilament rings create cleavage furrow

animals

cell plate forms

plants

why can’t plant cells pinch in cytokinesis

wall is rigid

end result of mitosis

2 genetically identical diploid cells

signals received by proteins in the plasma membrane to divide

growth factors

internal signaling proteins that increase or decrease the amount of cellular division that occurs

cyclins

(what cyclin) triggers cells to move from G0 to G1 and from G1 into S phase

Cyclin D

(what cyclin) prepares the cell for DNA replication in S phase

Cyclin E

(what cyclin) activates DNA replication inside the nucleus in S phase

Cyclin A

(what cyclin) promotes the assembly of the mitotic spindle and other tasks in the cytoplasm to prepare for mitosis

Cyclin B

enzymes that are always present in the cell, need activated by cyclin proteins, initiate different aspects of the cell cycle

cdk, cyclin dependent kinases

send sdks to m phase targets

m cyclins

stage in the eukaryotic cell cycle at which the cell examines internal and external cues and “decides” whether or not to move forward with division

checkpoints

checks to make sure that the cell has enough room, nutrients, organelles, also checks for DNA damage

G1 checkpoint

cell checks if chromosomes have attached correctly to mitotic spindle

M-phase checkpoint

checks if DNA replication has finished and for DNA damage

G2 checkpoint

stops cell division if DNA is damaged. tries to initiate DNA repair at first. can also stop cell cycle, called cell growth arrest

p53

controlled cell death. cell dies in order to stop cancer

apoptosis

enzymes, usually inhibited, that break down internal and external structures

caspases

uncontrolled cell growth

cancer

genes that code for proteins that promote the cell cycle and prevent apoptosis. become oncogenes when mutated

proto-oncogenes

genes that code for proteins that inhibit the cell cycle and promote apoptosis. when mutated, proteins don’t function correctly

tumor suppressor genes

cancer-causing substances that can lead to a mutation in DNA

carcinogens

cancerous mass of cells

tumor

cancer that doesn’t spread

benign

cancerous cells spreading

malignant

cancer cells move around the body causing the cancer to spread

metastasis

formation of blood vessels into tumor. allows cancer to spread

angiogenesis

cancer cells are _____ the same as normal cells

99.9%

treatment that uses powerful chemicals to kill fast-growing cells in your body

chemotherapy

removal of tumor

surgery

use of radiation to kill cancer cells

radiation therapy

using biotechnology to train/act like your own immune system to fight cancer

immunotherapy

the total number of chromosomes, which consists of two sets

diploid

half of the number of chromosomes found in the diploid cell. only one set of chromosomes

haploid

body cells

diploid

sex cells

haploid