2.02 Structure and Function of Cells

Cells are the basic unit of structure for all living things.

BACTERIA

BACTERIA

NO membrane-bound organelles

plasma membrane

cell wall

flagella

ribosomes

EUKARYOTICCELLS

Organelles

ANIMAL

PLANT

Structure and Function of Eukaryotic Cells

small, specializedstructures inside cellswith specific functions

Structure and Function of Eukaryotic Cells

CELL BOUNDARIES

PLASMA (CELL) MEMBRANEflexible boundary separating the inside of the cell from the surrounding environment

control what enters & leaves the cell

helps maintain HOMEOSTASIS

INSIDE

OUTSIDE

phospholipidsproteins

CELL BOUNDARIESCELL WALL

rigid structure found on the outside of the plasma membrane

provides protection & additional support

found in plants, bacteria, fungi, and some protists

Structure and Function of Eukaryotic Cells

Plasma membrane

Cell Wall

cellulose

Structure and Function of Eukaryotic Cells

Cytoplasm

clear, gelatinous fluid that fills the inside of the cell

most cellular processes occur in the cytoplasm

maintains shape of cell

organelles suspended in it

Structure and Function of Eukaryotic Cells

Nucleus

contains the DNA & controls what takes place inside of a cell

surrounded by a membrane

nuclear membrane

also contains the nucleolus

Structure and Function of Eukaryotic Cells

NucleolusNucleus

Chromatin

found inside the nucleusproduces the ribosomes

found inside the nucleusDNA, genetic information

chromatin chromosome

Structure and Function of Eukaryotic Cells

Ribosomes

made of RNA

synthesize (make) proteins

attached to “rough” endoplasmic reticulum

“free”, located in cytoplasm

Structure and Function of Eukaryotic CellsEndoplasmic reticulum

rough

smooth

series of folded membranes, attached to nucleus; transport material throughout cell

attached ribosomesmake proteins shipped throughout cell

no ribosomesproduce & store lipidsdetoxify poisons

Structure and Function of Eukaryotic Cells

Golgi apparatus (body)made of membranes – described as “stack of pancakes”

packages, stores, & ships out materials such as proteins and lipids

Roughendoplasmic

reticulumPlasma

membrane

Proteins for usewithin the cell

Proteins for useoutside the cell

Golgiapparatus

Vesicles

Proteinsecretion

Figure 4.12 The Golgi Apparatus

Structure and Function of Eukaryotic Cells

Vacuoles and Vesiclesmembrane-bound structurestemporary storage of food, water, enzymes, & other materials that enter / leave cell

Lysosomesmembrane-bound vesiclecontains digestive enzymesbreaks down waste, food, old organelles

Golgi apparatus Primarylysosome

Food particlesdigested

Extracellularenvironment

Plasmamembrane

Food particletaken in by

phagocytosis

Figure 4.13 Lysosomes Isolate Digestive Enzymes from the Cytoplasm

Products of digestion

Structure and Function of Eukaryotic CellsCELL ENERGY

Mitochondriabreaks down sugar molecules to produce energy

has 2 membranes

outer inner

has its own DNA

cellular respiration

Structure and Function of Eukaryotic CellsCELL ENERGY

Chloroplast

captures light energy & converts it to chemical energy (sugar molecules)

has 2 membranes

has its own DNA

photosynthesis

outer

innerthey are green because the contain the pigment CHLOROPHYLL

Structure and Function of Eukaryotic CellsCytoskeleton

maintains cell shape and support

help move structures around within the cell

microfilaments

microtubules

thin fibers made of the protein actin

long hollow cylinders made of the protein tubulin

Structure and Function of Eukaryotic Cells

CELL MOVEMENT

Flagella

Cilia

long, whip-like structure (“tail”)

short, hair-like structures

few in number (1 – 4)

very numerousalso used in feeding

ANIMAL CELL

mitochondrion

Golgi apparatus

nucleolus

nucleus

cytoplasmribosome

plasmamembrane

smooth ER(no ribosomes)

rough ER(endoplasmic

reticulum)

lysosome1.

2.

3.

4.5.

6.

7.8.

9.

10.

11. centrioles

12.vesicle

13. microtubule

PLANT CELL

cell wallplasma membrane

Golgi apparatus

chloroplast

central vacuolemitochondria

cytoplasm

rough ERnucleus

nucleolussmooth ER

ribosomes

1.

2.

3.

4.5.6.

7.

8.

9.

10.

11.

12.

Structure and Function

Nerve cells structure is well suited to carrying nerve impulses through the body.

Structure and Function

Red blood cells smooth disk shape is well suited to traveling through blood vessels.

Structure and Function

Muscle cells need a great deal of energy, so they have many mitochondria located in them.