Bio Test 3

what is a biofilm

clusters of bacteria stuck together- unicellular acting as multicellular

what is quorum sensing

‘power in numbers’ many unicellular acting together to bacteria to connect and coordinate aggression

what are the 3 stages of cell signaling

receptor, transduction and response

what happens in stage 1 cell signaling- reception

signal molecule connects to the receptor

What happens in stage 2 cell signaling- transduction

relay of molecules in signal transduction pathway

What happens in stage 3 cell signaling- response

activation of cellular response

what is a receptor

responds to stimulus- usually catalyzes something else

what is a ligand

signaling molecule

what structures are involved in signaling by direct contact

gap junctions in animals and plasmodesmata in plants

How does local signaling work

influence cells- either paracrine or autocrine

What is paracrine signaling

influencing near by cells- growth factors

What us synaptic signaling

type of local signaling where electricals impulses are converted into chemical neurotransmitter signals that then diffuse across a synapse

hormones in signaling

used in long distance signaling- circulatory system

what are hormones

substance secreted at one location that has an effect at a distant location

where are receptors

plasma membrane as inteagral membrane proteins

receptor binding to ligand

very specific- ligand must fit right on binding site and hve charges in correct places

how to g proteins linked receptors work

ligand binding outside triggers conformational change exposing g protein binding site on inside

steps on how g proteins work

1. hormones binding to the receptor activates the g protein, gtp replaces gdp

2. activated g protein activates an effector protein- reactants to products- amplifies

3. the gtp on g protein is hydrolyzed to gdp but remains bound to g protein

how do tyrosine kinase receptors work

1. the a subunit of the receptor bind insulin

2. conformational change in the b subunit transmits a signal to the cytoplasm of the insulin present

3. signal activates the receptor’s protein kinase domain in the cytoplasm

4. then phosphorylates insulin response substates- chemical cascade response

how do lignad gated ion channel receptors work

ligand binding triggers channel opening allowing channel specific ions to cross the membrane through concentration gradient

how do steroid receptors work

in cytoplasm or nucleus. acts as a transcription factor promoting expression of specific genes from dna in nucleus. mRNa made, exported to cytoplasm- then translated

what are kinases

enzymes that add phospahates

what are phosphatases

remove phosphates

what is a second messenger

small, non protein released as a result of ligand binding receptor

what are some examples of second messengers

cAMP

inositol triphosphate- IP3

Diacylglycerol

Ca++

what happens in the nuclear response to ligand binding

amplified signal leads to production of new rna and proteins

what happens in the cytoplasmic response

more activated molecules at each step

what is apoptosis

programed cell death

what are caspases

causes cellular structures to degrade

what is the cell cycle

mitosis

what types of cells undergo mitosis

eukaryotic

what is binary fission

prokaryotic cells way to divide

2 copies of the origin go to opposite sides and spilt

what is chromatin

long thin chromosome

what is a chromosome

DNA+Protein

what are sister chromatids

2 identical copies after replication

what is a centromere

thing holding the sister chromatids together

what is a centrosome

structure that become microtubules and pull the sister cromatids and latch at the top

what are the stages of the cell cycle

G1, DNA synthesis, G2, miosis/ cytokinesis

What happens in G1

cells grow

What happens in Dna Synthesis

dna is replicated

What happens in G2

right before it divides

what are the stages of mitosis

prophase, prometaphase, metaphase, anaphase, telophase/ cytokinesis

what happens in prophase

chromosomes condense, centrioles appear, and nucleus disappears

what happens in prometaphase

nucleus/ nuclear envelope disappear, spindle connects with centromere, top spindles anchor

what happens in metaphase

chromatids line up on metaphase plate

What happens in anaphase

chromatids are pulled apart

what happens in telophase

reestablish normal structures, and reform to do again

what is cytokinesis

the cell forming a cleavage furrow and separating into 2 cells

how is cytokinesis different in plants and animals

animals have the cleavage furrow and plants grow a cell plate to split

what is a kinetochore

where the spindle fibers attach to pull the sister chromatids apart

what is an orgin in bacteria

the part of the dna that copies and 2 pull apart

where the checkpoints located in each cell

G1, G2, M

how do cyclins and cyclin dependent kinases regulate the cell cycle

the build up to a certian point- trigger something to go- then drop again- and repeat

what do we mean when we say a cell is tranformed

the check fail, and a bad cell is made

what is metastasis

spreading throughout the body

what is the difference between a malignant and benign tumor

benign- not cancerous

what is the difference between mitotic and meiotic reproduction

meiosis results in 4 sex cells

what is a somatic cell

body cells- mitosis

what do somatic cells have

22 autosome chromosomes

and 1 pair of sex cells

what is a germ line cell

gametes- sex cells

what is an autosome

22 chromosome pairs

not sex cells

what is a sex chromosome

determines sex

either xx or xy

what are homologous chromosomes

paired chromosomes

what are sister chromatids

2 identical copies of the same chromosome

what is karyotyping

looking for genetic defects

what is a haploid

cell that contains a single set of chromosomes

what is a diploid

2 complete sets of chromosomes

what is a gamete

sex cells

what is a syngamy

fusion of 2 cells in reproduction

what is a zygote

a diploid cell resulting in the fusion of 2 haploid gametes

how are haploid cells produced

meiosis

what are the phases of meiosis

meiosis 1- interphase, prophase 1, metaphase 1, anaphase 1, telophase1

meiosis 2- prophase 2, metaphase2, anaphase 2, telophase 2

telophase 2

becomes 4 haploid cells with only one chromatid in each

anaphase 2

2 haploid daughter cells

sister chromatids separate and pull to opposite ends

metaphase 2

2 haploid daughter cells

line up on metaphase plate

prophase 2

2 haploid daughter cells

- chromosomes line up and condense

telophase 1

separate and form 2 haploid daughter cells

anaphase 1

homologous pairs move to separate ends

prophase 1

chromosomes condense and pair up and crossover

metaphase 1

homologous pairs line up at metaphase plate

what is synapsis

pairing of homolougous chromosomes

what is a tetrad

each pair of chromosomes- 4 chromatids

what is a synaptonemal complex

protein zipper that forms between homologous chromosomes

when does crossover occur

prophase 1

what is independent assortment

many choices

move randomly and go to deferent poles

diversity

what is an outcross

transfer of gametes to a genetically deferent individual

what is a self cross

fusion of male and female gametes of the same organism

what is a test cross

cross between individual showing recessive trait and one displaying dominate trait to determine if the dominate trait is heterozygous

what is a backcross

cross between hybrid with a parent to acchive the results close to the parent

what is P generation

parental

What is F1 Generation

result of parents

what Is F2 generation

result of crossing f2

What is a dominate trait

trait that overrides

what is a recessive trait

trait that gets overridden

what is a codominant trait

neither recessive or dominate

what is an incompletely dominate trait

both alleles of a gene at a locus are partially expressed

what is a genotype

complete set of all genes transferred from parents

what is a phenotype

observable characteristics

what is an allele

matching genes- do the same thing

what is homozygous

matching at locus