Cell Structure and

Function

Prokaryotebacteria cellsProkaryote

bacteria cellsTypes of cells

Eukaryoteanimal cellsEukaryote

animal cellsEukaryoteplant cellsEukaryoteplant cells

Cell characteristics All cells:

are surrounded by a plasma membrane

have cytoplasm cytoplasm = cytosol + organelles

contain DNA

have ribosomes tiny “organelles” that make proteins using

instructions contained in genes

4

Eukaryotes Prokaryotes

DNA Associated with protein in membrane-bound nucleus

single circle.

“naked”

Size 5-100 µm 0.2-10 µm

Organization Single and multicellular, some have cell walls

single-celled, all have cell walls

Division Mitosis and Meiosis Binary Fission

Organelles membrane bound organelles like mitochondria

no organelles, different ribosomes (70S)

Examples plants, animals, protists, fungi

bacteria, archaea

Eukaryotic -

Animal Cell

Eukaryotic -

Plant Cell

2.2.12.2.2

Prokaryotic Cell

E. coli ultrastructure (SEM) 2.2.3

Prokaryotic Cells divide by binary fissionProkaryotic Cells divide by binary fission

2.2.4

Representative Animal Cell

Drawing of animal cell. 2.3.1 and 2.3.2

Representative Plant Cell

Liver Cell (SEM)Liver Cell (SEM)

2.3.3

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Animal Plant

Cell Wall No, only plasma membrane

Yes, and plasma membrane

Chloroplasts no yes

Polysaccharides Glycogen Starch as storage

Cellulose for structure

Vacuole no Large fluid filled present

Shape Able to change shape. Usually

rounded.

Fixed shape.

Usually regular.

2.3.4

Cell MembraneCell Membrane

Structure: phospholipid

bilayer proteins that

function as channels, markers, and receptors.

Function: selectively

permeable boundary between the cell and external environment

NucleusNucleus

Structure: membrane bound

sphere that contains DNA and nucleolus

Function: storage center of cell’s DNA manages cell

functions

Cell WallCell Wall

Structure: Rigid wall made up of

cellulose, proteins, and carbohydrates

Function: Permeable boundary

around the outside of the plant cell membrane that provides structure and support

CytoskeletonCytoskeleton

Structure: a network of thin,

fibrous elements made up of microtubules and microfilaments

Function: acts as a support

system for organelles

maintains cell shape

RibosomesRibosomes Structure:

consist of two subunits made of protein and RNA

Function: location of protein

synthesis

Endoplasmic ReticulumEndoplasmic Reticulum Structure:

a system of membranous tubules and sacs

Function: intercellular

highway (a path along which molecules move from one part of the cell to another)

Rough Endoplasmic ReticulumRough Endoplasmic Reticulum

Rough Endoplasmic Reticulum (rER): prominent in cells

that make large amounts of proteins to be exported from the cell

Covered with ribosomes

Smooth Endoplasmic ReticulumSmooth Endoplasmic Reticulum Smooth

Endoplasmic Reticulum (sER): involved in the

synthesis of lipids and breakdown of toxic substances

Not covered with ribosomes

Golgi ApparatusGolgi Apparatus Structure:

stacked flat sacs

Function: receives vesicle bound

proteins from the rER and distributes them to other organelles or out of the cell

receiving, processing, packaging, and shipping

AKA: Golgi body, Golgi complex or dictysome

LysosomesLysosomes

Structure: spherical organelles

that contain digestive (hydrolytic) enzymes

Function: breaks down food

particles, invading objects, or worn out cell parts

VacuolesVacuoles Structure:

a sac of fluid surrounded by a membrane

Function: used for

temporary storage of wastes, nutrients, and water

MitochondriaMitochondria

Structure: folded membrane

(cristae) within an outer membrane.

Function: converts energy

stored in food into usable energy (ATP)

Allows aerobic cellular respiration

ChloroplastsChloroplasts Structure:

stacked sacs (thylakoids) that contain chlorophyll surrounded by a double membrane

Function: photosynthesis

(conversion of light energy to chemical energy stored in the bonds of glucose)

Mitochondria & Chloroplasts Important to see the similarities

transform energy generate ATP

double membranes = 2 membranes semi-autonomous organelles

move, change shape, divide internal ribosomes, DNA & enzymes

Lynn MargulisU of M, Amherst

Endosymbiosis theoryEvolution of eukaryotes

Any Questions??

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