OLI AP Unit 3 Module 6 the cell-membranes

the cell,

cell

basic structural unit of living things

alive

able to maintain homeostasis

homeostasis

relatively constant internal state

current cell theory

1. all known living things are composed of one or more cells

2. all new cells are created by pre-existing cells dividing in 2

3. cell is most basic unit of structure and function in all living organisms

all functions essential to life

occur within the cell

cell division

cell contains and transmits to next generation info necessary to conduct and regulate cell functioning

each animal cell has

cell membrane

cytoplasm

organelles

organelle

carries out specialized tasks in cell

replication, energy production, protein synthesis, food and waste processing

cell types differ in

arrangement and number of organelles

physical structure

cell shape and structure

intermediate filaments

microtubules

microfilaments

centrosome

centrosome

has pair of microtubule bundles called centrioles

near nucleus

centrioles

move chromosomes to opposite ends of cell during mitosis

ribosomes

protein synthesis

scattered in cell or attached to rough ER

when a protein is manufactured it needs

to be folded into a specific shape

side chains of carbohydrates or lipids may be added

to be delivered to specific locations

process of protein synthesis

ER- protein formed

golgi apparatus- completes protein processing, packages it into vesicle for transport

smooth ER

lipid synthesis

breakdown of toxins

golgi apparatus

processes and packages proteins for transport

makes lysosomes

lysosome

vesicle

takes in cell debris and waste and destroys it

has powerful hydrolytic enzymes that could destroy the cell

mitochondria

generates ATP for cell

has mitochondrial DNA/mDNA

can replicate

nucleus

has DNA of cell

has nucleolus

surrounded by nuclear membrane/nuclear envelope with nuclear pores

anucleate cell

no nucleus

multinucleate cell

multiple nuclei

nucleolus

makes ribosomes

DNA of cell

genetic code for making every protein in body

phospholipid structure

a polar head and 2 nonpolar fatty acid tails

hydrophobic core of bilayer diffusion

no diffusion of hydrophilic ions and polar molecules

diffusion of small hydrophobic molecules and gases

phospholipid membrane fluidity

allows cell to change shape

growth and movement

ability of a molecule to pass through the membrane depends on

polarity

size

what flows easily through membrane

non-polar molecules

oxygen, carbon dioxide, small hydrocarbons

what is stopped from flowing through membrane

polar substances

charged ions

fluidity of cell membranes is dependent on

temperature

concentrations of saturated and unsaturated fatty acids

saturated fatty acids

make membrane less fluid

unsaturated fatty acids

make membrane more fluid

membrane protein functions

transport

communication

metabolism

adhesion

membrane proteins transport

larger materials

hydrophilic molecules

2 categories of membrane proteins

integral membrane proteins

peripheral proteins

integral membrane proteins

embedded in lipid bilayer

soluble in nonpolar, hydrophobic solvents

pores that selectively allow ions, nutrients, and wastes into or out of cell

transmit signals across membrane into and out

sense extracellular environment

peripheral proteins

on only one side of membrane

attached to integral proteins

can be anchor points for cytoskeleton or extracellular fibers

can be glycoproteins

glycosylation

process where carbohydrates are added to lipids and proteins

oligosaccharides

chains of 15 or fewer sugar molecules

give cell identity

are distinguishing factor in human blood types and transplant rejection

distribution of membrane carbohydrates is

asymmetric

extracellular side of membrane

in contact with extracellular fluid

has oligosaccharides that identify the cell

has end of integral proteins

inner membrane

in contact with cell contents

has few carbohydrates

anchors to the cytoskeleton

has end of integral proteins

biological membrane

a collage of different proteins embedded in fluid matrix of lipid bilayer

lipid bilayer

main fabric of membrane

structure makes a semipermeable membrane

hydrophobic core

impedes diffusion of hydrophilic structures

allows diffusion of hydrophobic molecules