Bio Unit 4 Notes

function, structure

cell-to-cell communication is critical for the _____ and _____ of cells

growth, development

cell communication is responsible for_____ and _____ of multicellular organisms

direct contact
local signaling
long distance signaling

what 3 ways do cells communicate?

direct contact

communications through cell junctions

freely, adjacent

signaling substances and other materials dissolved in the cytoplasm can pass _____ between _____ cells

animal cells

gap junctions

plant cells

plasmodesmata

local regulators

a secreting cell will release chemical messages that travel a short distance through extracellular fluid

response, target

the chemical messages will cause a ______ in a ______ cell

paracrine signaling
synaptic signaling

examples of local regulators

paracrine signaling

secretory cells release local regulators via exocytosis to an adjacent cell

synaptic signaling

occurs in animal nervous systems

hormones

what do animals and plants use for long distance signaling?

paracrine signaling

what type of communication involves a cell secreting a substance to an adjacent cell?

plasmodesmata

what structures can plant cells in direct contact with each other diffuse substances through?

reception, transduction, response

what are the 3 stages of cell signaling?

reception

cell signaling stage 1

transduction

cell signaling stage 2

response

cell signaling stage 3

receptor

macromolecule that binds to a signal molecule (ligand)

immune cells

what is an example of direct contact?

antigen presenting cells

APCs

T cells

APCs communicate to _____ through direct contact

ligands

chemical messages

vascular tissue, air

plants release hormones that travel in the plant's ____ _____ or through the ____ to reach target tissues

animals

who uses endocrine long distance signaling?

circulatory system

in animals, where do specialized cells release hormones into to reach target cells?

insulin

released by pancreas into blood stream where it circulates through body and binds to target cells

interacts, transmits

all receptors have an area that _____ with the ligand and an area that _____ a signal to another protein

ligand, receptor, specific

in reception, binding between ____ and ___ is highly __sarahaddthishere____

activates

when the ligand binds to the receptor, the receptor ______

interact with other molecules

what does activation allow the receptor to do?

plasma membrane, intracellular

receptors can be in the _____ or ______

hydrophobic

steroid hormone means....

plasma membrane receptors

what is the most common type of receptor involved in signal pathways?

intracellular receptors

binds to ligands that can pass through the plasma membrane

transduction

the conversion of an extracellular signal to an intracellular signal that will bring about a cellular response

signal transduction pathway

what does transduction require?

protein

what type of activity does the signal transduction pathway regulate?

phosphorylation by protein kinase

what does the signal transduction pathway regulate protein activity through?

amplified

during transduction the signal is_______

second messengers

small, nonprotein molecules and ions help relay the message and amplify the response

response

the final molecule in the signaling pathway converts the signal to a response that will alter a cellular process

membrane permeability, metabolic process, on, off

examples of response
a. protein that can alter _____ ______
b. enzyme that will change a ______ _____
c. protein that turns genes ______ or ______

how cell responds to env

what can signal transduction pathways influence?

gene expression, cell function

what can signal transduction pathways result in changes in? 2 things

ligands and receptors can only bind to their specific match

what does it mean that receptor binding is highly specific?

ligand, receptor, intracellular

in the first stage of cell signaling _____ binds to a ______, which can either be in the plasma membrane or_________

cellular response

in the second stage of signaling, the signal is converted and it will bring about a ____________

cellular response

in the third stage of signaling, the final molecule in the signaling pathway will convert the signal to a response that will alter a(n) ________

GPCRs, ion channels

what are the two main categories of cell membrane receptors in eukaryotic organisms?

G protein coupled receptors

largest category of receptors
important to a g protein that can bind to GTP

GPCRs

g protein coupled receptors

inactive

the GPCR, enzyme and G protein are ____ until ligand binding to GPCR on the extracellular site

cytoplasmic

ligand binding causes ________ side to change shape

ligand gated ion channels

what is located in the plasma membrane?

plasma membrane

where are ligand gated ion channels located?

in nervous system

why are ligand gated ion channels important?

gate

receptors that act as a _________ for ions

internal

the body must be able to monitor its _____ conditions at all times

set points

values for various physiological conditions that the body tries to maintain
this has a normal range

homeostasis

the state of relatively stable internal conditions
organisms detect and respond to a stimulus

negative, positive

there are two times of feedback loops: _____ and ______

stimulus

a variable that will cause a response

receptor/sensor

sensory organs that detect a stimulus. this information is sent to the control center (brain)

effector

muscle or gland that will respond

response

changes the effect of the stimulus (decrease or increase it)

negative feedback

what is the most common feedback mechanism?

positive feedback

type of feedback increases effect of stimulus

genetic disorders
substance abuse
intolerable conditions

reasons why the body may not be able to regulate homeostasis

disease

when the body is unable to maintain homeostasis

negative

blood glucose levels is an example of _______ feedback

cell reproduction/growth, tissue repair

what does the cell division process/ the cell cycle allow for?

DNA

cells must organize and package their ______ before division

proteins, histones, nucleosomes

DNA associates with and wraps around _____ known as _____ to form ________

chromatin

what do strings of nucleosomes form?

chromatin

when a cell is not actively dividing, _____ is in a non-condensed form (spaghetti)

chromatin, chromosome

after DNA replication, _______________ condenses to form a ______

each chromosome

since the DNA was replicated, ____ _______ has a duplicated copy

sister chromatids

the copies of DNA join together to form _____

centromere

the region on each sister chromatid where they are most closely attached

kinetochore

proteins attached to the centromere that link each sister chromatid to the mitotic spindle

genome

all of a cell's genetic information

prokaryotes

singular, circular DNA

eukaryotes

one or more linear chromosomes

homologous chromosomes

two chromosomes
(one from mom and one from dad) that are the
same length, have the same centromere position,
and carry genes controlling the same
characteristics

alternating phases of
interphase and mitosis

what does the cell cycle consist of?

G1 first gap phase

The cell grows and carries out normal functions

S synthesis phase

DNA replication and chromosome duplication
occurs

G2 second gap phase

Final growth and preparation for mitosis

mitosis

1. Prophase
2. Prometaphase
3. Metaphase
4. Anaphase
5. Telophase and cytokinesis

cytokinesis

cytoplasm divides

2 identical diploid daughter cells

what does mitosis result in?

prophase, prometaphase, metaphase, anaphase, telophase

5 stages of mitosis

prophase

When does chromatin condense?

prometaphase

when do microtubules enter the nuclear area and some attach to kinetochores?

cleavage furrow

how does cytokinesis occur in animals?

vesicles

how does cytokinesis occur in plants?

cohesins

what proteins are responsible for holding the sister chromatids together?

s phase

what phase of the cell cycle is DNA copied in?