Download Prokaryotes vs

Prokaryotes vs. Eukaryotes
Prokaryotes –
 Have no nucleus or membrane-bound organelles
 Mostly bacteria (ex: tuberculosis, strep throat
 Can live in extreme environments (ex: Hot springs)
 Do have DNA – forms a loop floating around the cell
 Many do photosynthesis/chemosynthesis and some don’t like oxygen
Eukaryotes
 Have a membrane- bound nucleus
 Have membrane-bound organelles
 Animals, plants, fungi, and protests
PLANT CELLS
Plant cells are like animal cells, but their shape is often more defined
They do have DNA and nuclei and cell membranes
Extra parts
1. cell wall – the cell wall is outside the membrane, made of cellulose, keeps cells
rigid
2. Vacuoles – large organelles that store enzymes and waste, some in plants store
water, usually plant cells have one large one.
3. Plastids – have their own DNA and can store fats or pigments )can cause the
colors in flowers and fruits)
4. Chloroplasts – a type of plastid that stores the pigment chlorophyll and does
photosynthesis
CELL MEMBRANE
-
selectively permeable
structure – phospholipids bilayer (phosphate / fats & oils / 2 layers)
A. self – healing ( a rip in the cell membrane molds back together)
B. Fluid Mosaic model
C. Has proteins in it for stability
a. Integral – goes all the through the membrane
b. Peripheral – attached to either the outer or inner layer
Selectively Permeable
Selectively permeable - lets only some things permeate it so basically it “selects” what it
allows to go through it. Usually things move through by diffusion
Your cell membrane is selectively permeable
- things like water and some mineral diffuse across it
- things like toxins and large particles can’t diffuse across it
Your cell membrane tries to be a barrier to keep harmful things from diffusing into the
cell, while allowing good things in
What if something is too big to diffuse through the cell membrane? (Like starch through
the plastic bag)
- endocytosis
- facilitated diffusion – carrier proteins “carry” it through the membrane
Endo – in/inside
Exo – out/outside
Cyto – cell
Cytoplasm – the goop in the cell where the organelles are
Getting things in and out of the cell
-endocytosis : getting stuff in the cell (food, etc.) - can happen by diffusion
- exocytosis : getting stuff out of the cell (waste, etc.)
*All organelles other than ribosomes or the cytoskeleton have a membrane around them
(membrane bound).
A few more parts:
1. Golgi Apparatus – packages things (like waste) to send out of the cell. Puts the
membrane around a vesicle for exocytosis
2. Ribosomes – made of RNA and protein – they read RNA and make proteins
3. Mitochondria – use to make ATP (battery for chemical reactions). You find
more of them in active cells like muscle cells
4. Nucleus – like the brain of the cell
a. Membrane around nucleus is called nuclear envelope
b. Inside nucleus is a mix of DNA and protein called chromatin
c. RNA goes in and out of nucleus through nuclear pores