Unit 2 - Cell Structure and Function (AP BIO)

Prokaryotes VS Eukaroytes

Pro:

• single circular chromosome

• no membrane bound organelles

• small

• if wall is present: peptidoglycogen

DNA

Plasma membrane

ribsomes

cytoplasm

cell wall (only in plants)

nuecloid

Euk:

• multiple linear chromosome

• membrane bound organelles

• large

• if wall is present:

  • plants: cellulose

  • fungi: chitin

Nucleus

structure: double membrane

function": store genetic info and synthesize transcription

Rough ER

structure: embedded with ribosomes

function: site of protein synthesis, cell compartmentalization, and intracellular transport

Smooth ER

structure: folded, tubelike structure without ribosomes

function: detoxification, calcium storage, and lipid synthesis

Golgi Complex

structure: membrane-bound structure composed of sacs

function: modify, transport, and package proteins and lipids

Mitochondria

structure: double membrane (outer: smooth, inner: folded)

function: site of oxidative phosphorylation & kreb cycle, and makes ATP

Chlorplast

structure: double outer membrane

function: site of photosynthesis, site of glycosis

• only in plant cells

Lysosome

structure: membrane enclosed sacs that contain hydrolytic enzymes

function: intracellular digestion

Vacuole

structure: membrane-bound sacs

function: storage/release of macromoleucles or waste

Cell Wall

function: provide structural support, shape, and protection

• only in plant, fungi, or bacterial cells

cell membrane/plasma membrane

function: selective barrier and provided protection for cells

Endomembrane system

A series of membranous organelles in eukaryotic cells that work together to modify, package, and transport lipids and proteins. -

• endoplasmic reticulum, Golgi apparatus, lysosomes, vesicles, and plasma membrane

Cell Size

surface area: how much of the membrane interact w/extracellular environment

Volume: how quickly substances can diffuse into the cell

↑ SA/V = more efficiency

Endosymbiotic Theory & 7 Pieces Of Evidence

mitochondria & chloroplasts were once independent prokaryotic cells. Formed a mutualistic relationship w/another cell → evolution of eukaryotes

• have circular DNA

• have double membrane

• have prokaryotic ribosomes

• similar size as prokaryotes

• divide by binary fission

• M is related to purple bacteria

• C is related to cyanobacteria

Simple Diffusion

passive transport

doesn’t require enegy

↑ to ↓ concentration

↓ concentration gradient

no transport protein needed

small and nonploar

ex: CO2, O2, N2, steriods

Facilitated Diffusion

passive transport

doesn’t require energy

↑ to ↓ concnetration

down concentration gradient

needs transport proteins

• channels/carriers

ex: Na+, K+, Ca+, H+

Active Transport

requires energy

against concentration gradient

↓ to ↑ concentration

requires transport proteins

• carriers

ex: Na+, K+, Ca+, H+

Endocytosis

process by which cells engulf substances, bringing them into the cell in vesicles. It includes forms such as phagocytosis (eating) and pinocytosis (drinking)

Exocytosis

the process by which cells expel substances, releasing them outside the cell in vesicles.

• important forcell communication and waste removal.

Osmosis

the diffusion of water across a selectively permeable membrane

↑ to ↓ concnetration

Hypertonic:

• ↑ solute & ↓ water

• shrink because water moves out the cell

Isotonic:

• equal amount of solute and water

Hypotonic:

• ↑ water & ↓ solute

• swell because water moves into the cell