bio exam 2

Lack membrane; enclosed cell

prokaryotic cell

no nucleus

prokaryotic cell

generally smaller in size

prokaryotic cell

bacteria and archaea

prokaryotic cell

single celled

prokaryotic cell

structurally complex

eukaryotic cell

enclosed compartments: organelles

eukaryotic cell

DNA in nucleus

eukaryotic cell

animals, plants, fungi, protists

eukaryotic cell

chromosomes

where dna is organized

chromatin

DNA+proteins in chromosomes

Nucleolus

made up of rNA + proteins and are where ribosomes are made

Ribosomes

make proteins
in prokaryotes + eukaryotes

ribosome input

mRNA

ribosome output

protein

mRNA

messenger RNA;
tells the body how to make protein

tRNA

transfer RNA; type of RNA that carries amino acids to the ribosome

rRNA

ribosomal RNA; type of RNA that makes up part of the ribosome

Rough ER

produces proteins, filled with ribosomes
distrubtes transport vesicles

Smooth ER

Synthesizes lipids

Golgi apparatus

shipping center of cell
modifies products of the ER, manufactures certain macromolecules, sorts and packages materials into transport vesicles

vesicle

A membrane bound sac (lipid bilayer) that contains materials involved in transport of the cell.

vacuole

Stores materials
Type of vesicle
formed from ER + golgi apparatus

food vacuole

digests food particles ingested by the cell
phagocytosis

contractile vacuole

The cell structure that collects extra water from the cytoplasm and then expels it from the cell

lysosome

An organelle containing digestive enzymes
form from golgi complex

central vacuole

plant cell
holds materials and wastes
provide structure and support for growing plant.

mitochondria

sites of cellular respiration, generates ATP

cristae

folds in the inner membrane of mitochondria
large surface area for enzymes that synthesize ATP

mitochondrial matrix

inner membrane of mitochondria
aids in cellular respiration (has enzymes for cellular respiration)

contains chlorophyll

chloroplast

chloroplasts

(plants and algae)
site of photosynthesis

thlyakoid

saclike photosynthetic membranes found in chloroplasts
helps absorb sunlight for photosynthesis

granum

stack of thylakoids

stroma

internal fluid in chloroplast

peroxisome

organelle with various specialized metabolic functions; produces hydrogen peroxide as a by-product, then converts it to water

cell wall

plant cells
protects plant cell, maintains its shape, prevents excessive uptake of water

primary cell wall

thin & flexible

secondary cell wall

added between plasma membrane and primary cell wall

middle lamella

thin later between primary walls of adjacent cells

plasmodesmata

channels that pierce plant cell walls
water and small solutes can pass from cell to cell

extracellular matrix

network of proteins and other materials that surround, support, and give structure to cells
ANIMAL CELLS

integrins

receptors that bind to the ECM

cell junctions

cells interacting/communicating

tight junctions

limit what passes through cells

desmosomes

patches that holds cells together

gap junctions

allows ions to pass through cells

cytoskeleton

network of fibers throughout cytoplasm

microtubules

thickest part of cytoskeleton
grow + shrink
attach to chromosomes (helps in cell division)

intermediate filaments

maintain structure
do not shrink + grow

centrioles

9 triplets of microtubules arranged in a ring
"microtubule organizing center"

microtubules grow from \____ near the nucleus

centrosome

cilia

Hairlike projections that extend from the plasma membrane and are used for movement
Eukaryotic cells

flagella

A long, whip-like filament that helps in cell motility
eukaryotic + prokaryotic cells

endosymbiotic theory

host cell + prokaryotic cell merged \= eukaryotic cell with mitochondrion

what is the plasma membrane made out of?

lipids and proteins

endomembrane system

many membrane-bound organelles connected by vesciles
protein secretory pathway (exocytosis)

what organelles are apart of the endomembrane sysyem

nuclear envelope
ER
Golgic apparatus
lysosomes
vacuoles
plasma membrane

fluid mosaic model

model that describes the arrangement and movement of the molecules that make up a cell membrane
proteins + lipids will combine

integral proteins

"gateway to cell"
occupy hydrophilic and hydrophobic interior of the membrane

transmembrane proteins

Integral proteins that span the membrane.

integral and transmembrane proteins are \___

amphipathic
(hydrophilic + hydrophobic parts)

peripheral proteins

bound to the surface of the membrane

transport proteins

allow passage of hydrophilic substances across membrane

influence of temperature on lipids

in cold, lipids are less fluid

phospholipids
\___ head

hydrophobic

phospholipid
\___ tail

hydrophilic

cholesterol

moderates fluidity at different temperatures

6 functions of membrane proteins

1. Transport
2. Enzymatic activity
3. Signal transduction
4. Cell to cell recognition
5. Intercellular joining
6. Attachment to cytoskeleton and ECM

passive transport

the movement of substances across a cell membrane without the use of energy by the cell

diffusion

molecules spread out evenly into available space
molecules move DOWN concentration gradient (high to low)

dynamic equilibrium

number of molecules moving from left to right is equal

osmosis

Diffusion of water through a selectively permeable membrane

aquaporins

allow water to flow in and out of cells

facilitated diffusion

Movement of molecules along concentration gradient (selective)

channel proteins

transport protein
lets water or small ions through membrane quickly

carrier proteins

bind specific solutes and transfer them across the lipid bilayer
change shape

tonicity

the ability of a surrounding solution to cause a cell to gain or lose water

hypertonic

Solute concentration is greater than that inside the cell; cell loses water

hypotonic

Solute concentration is less than that inside the cell; cell gains water

isotonic

Solute concentration is the same as that inside the cell

active transport

moves substances across membrane against their concentration gradient
requires energy (ATP)

sodium-potassium pump

exchanges Na+ for K+ across the plasma membrane of animal cells

electrogenic pump

a transport protein that generates voltage across a membrane

membrane potential

voltage across membrane

cotransport

The connecting parts of the "downhill" diffusion of one substance to the "uphill" transport of another against its own concentration gradient.

bulk transport

requires energy
large molecules cross membrane

exocytosis

endomembrane system
transport vesicles go to membrane, fuse with it, and release its contents

endocytosis

process by which a cell takes material into the cell by infolding of the cell membrane

phagocytosis

"cellular eating"

pinocytosis

"cellular drinking"

receptor-mediated endocytosis

import macromolecules from the extracellular fluid

local signaling animal cells

gap junctions

local signaling plant cells

plasmodesmata

paracrine signaling

Signal released from a cell has an effect on neighboring cells.
animal cells
travel short distances

hormones

long distance signaling
hormone molecules are released that travel via circulatory system
can bind to the membrane or pass through the membrane

reception

detection of signal

transduction

conversion of the signal to a cellular response, via a signal transduction pathway

response

response to signal

ligand

signal molecule