AP BIO UNIT 2

Cell

simplest collection of matter that is alive

Plasma membrane

semi-permeable membrane

Semi-permeable membrane

allows some substances to cross while others cannot

Chromosomes

genetic material

Ribosomes

small structures that build protiens

Prokaryotes

single-celled organisms

Eukaryotes

multi-cellular organisms

Nucleoid

region where DNA is located (not surrounded by a cell membrane)

Prokaryotic chromosomes

circular

Capsule

jelly like coating of many prokaryotes

Eukaryotic chromosomes

linear

Organelles

specialized compartments in a cell

Eukarya

domain with eukaryotic organisms

Archaea

domain with prokaryotes that can survive in extreme enviornments

Bacteria

domain with prokaryotes notable for disease

Plant cells

have a cell wall, large central vacuole, choloroplast

Animal cells

have centrioles and lysosomes

Endomembrane system

membrane-bound organelles

Chromatin

complex of DNA and protiens

Nuclear pores

make holes in the nuclear envelope

Nuclear envelope

double membrane around the nucleus

Rough ER

assembles protiens

Lumen

inside of the ER

Bound ribosomes

secreted, incorporated, hydrolytic enzymes

Free ribosomes

remain in the cytosol

Smooth ER

synthesizes lipids

Smooth ER (sometimes)

detoxifying the cell

Golgi apparatus

modifies, stores, and sends protiens in transport vesicles

Cisternae

flattened membranous sacs that make up the Golgi

Cis face

face that receives vesicles from the ER

Trans face

face that ships vesicles off to other parts after contents are motified

Lysosome

digests and breaks down macromolecules

Hydrolytic enzymes

produced by the rough ER and used in lysosomes

Lysosome functions

fuse with food vacuoles and recycle cell components

Apoptosis

when a cell programs itself to die (lysosomes release acidic enzymes)

Vacuoles

large vesicles created in the ER and Golgi

Food vacuoles

formed by phagocytosis

Contractile vacuoles

pump excess water out of cells

Large central vacuole

store water, nutrients, pigments, and waste

Internal membranes

facilitate cellular processes and localize

Intermembrane space

space between two membranes of the mitochondrion

Mitochondrial matrix

inside the inner matrix

Cristae

folds in the membranes of the mitochondria

Mitochondria

creates ATP

Aerobix cellular respiration

oxygen causes sugar to be broken down into carbon dioxide, water, and ATP

Chloroplast

used for photosynthesis

Thylakoids

flattened, interconnected sacs

Granum

a stack of thylakoids

Stroma

fluid outside of the thylakoids

Thylakoid space

space inside the thylakoids

Chlorophyll

green pigment

Photosynthesis

conversion of light, carbon dioxide, and water into a carbohydrate (sugar) and oxygen

Endosymbiotic theory

prokaryote (ancestor of eukaryote) cell engulfed a aerobic prokaryote and created the mitochondria

Cytoskeleton

network of fibers in the cytoplasm

Cytoskeleton function

support the cell, maintain shape, anchorage, movement

Microtubules

thickest of the cytoskeleton

Microfilaments

actin filaments, thinnest component

Intermediate filaments

fibers with diameters in the middle

Flagella

long protrusions, one per cell

Cilia

shorter protrusions in large numbers

Cell wall

protects the plant cell, maintains shape, prevents excessive water, holds plant against gravity

Cellulose

polysaccharide that makes up the cell wall in plants

Peptidoglycan

polymer that makes up cell wall in bacteria

Plasmodemated

channels that connect plant cells

Tight junctions

plasma membrane of two cells are pressed tightly together

Desmosomes

rivets that fasten cells together into strong sheets

Gap junctions

membrane proteins create pores or channels that let small molecules move between cells

Fluid-mosaic

describes fluidly of membrane and components to show how they move freely around one another

Peripheral protiens

found on the inner membrane surface

Integral protiens

partially or wholly embedded in the membrane

Amphipathic

hydrophobic and hydrophilic regions

Cholestrol

controls the fluidity and movement

Low temperature cholesterol

more fluid, less rigid

High temperature cholesterol

less fluid, more rigid

Carbohydrate chians

allows cell to recognize one another

Glycoprotiens

proteins attached with carbohydrate chains

Glycolipids

phospholipids attached with carbohydrate chains

Channel protiens

allow specific molecules to pass through

Carrier protiens

combine with the molecule being transported and assits it’s passage

Cell Recognition Protien

helps cells identify each other

Receptor protien

responds to signals from other cells, specifically shaped

Enzymatic Protien

catalyzes specific reactions

Junction protien

attaches to adjacent cells so tissues can function

Can cross through easily

small, hydrophobic molecules

Cannot pass through easily

large, polar, and charged

Concentration gradient

concentration of particle in one area is higher than it is in another

Diffusion

net movement of molecules down a concentration gradient

Dynamic equilibrium

no net movement

Osmosis

diffusion of water

Aquaporins

integral membrane proteins that help water molecules travel more easily

Isotonic

no net gain or loss

Hypotonic

concentration of solute is higher than in cell

Hypertonic

concentration in cell is higher than solute

Facilitated transport

membrane proteins allows movement of substances that cannot pass through the membrane to go down the gradient

Water potential

measurement of free energy in a mole of water

Free energy

amount of energy available to do work

Active transport

movement of substances against the concentration gradient

Electrochemical gradient

difference in chemical and charge concentrations across a membrane

Transport vesicles

pieces of the membrane that encircle and transport large cargo

Exocytosis

takes things out of the cell