Cell IntroductionCell Introduction

• Prokaryotic CellProkaryotic Cell: A cell that is lacking : A cell that is lacking a nucleus and most organellesa nucleus and most organelles

• Eukaryotic CellEukaryotic Cell: A cell that contains a : A cell that contains a membrane bound nucleus and other membrane bound nucleus and other membrane bound organelles. membrane bound organelles.

• OrganellesOrganelles: “mini-organ” part of the : “mini-organ” part of the cell with a specific job. cell with a specific job.

Prokaryotic CellsProkaryotic Cells• A cell that lacks a nucleusA cell that lacks a nucleus

• Still has Genetic information (DNA) just Still has Genetic information (DNA) just not contained in the nucleusnot contained in the nucleus

• Bacteria and archaea are two types of Bacteria and archaea are two types of prokaryotic cellsprokaryotic cells

• These appear to be the earliest These appear to be the earliest organisms on earth. organisms on earth.

Eukaryotic CellsEukaryotic Cells• A cell with a membrane bound A cell with a membrane bound

nucleus and membrane bound nucleus and membrane bound organellesorganelles..

• Genetic material is contained in Genetic material is contained in the nucleusthe nucleus

• These are broken up into Plant These are broken up into Plant cells and Animal cellscells and Animal cells

Two Basic types Cell membrane

cytoplasm

Cell membrane

cytoplasm

nucleus

Cell organelles

Prokaryote

Eukaryote

Prokaryotes Eukaryotes

Cell membraneRibosomesCell wall

NucleusEndoplasmic reticulumGolgi apparatusLysosomesVacuolesMitochondriaCytoskeleton

Compare and Contrast

Animal cell -Eukaryote

Plant cell - Eukaryote

Cell TheoryCell Theory• The generalization that: The generalization that:

• all living things are all living things are composed of cellscomposed of cells

• cells are the cells are the basic unit of basic unit of structure and function structure and function in in living things.living things.

• All cells come from All cells come from existing cellsexisting cells

Cell OrganellesOrganelle: “Mini” organ

Nucleus• A large organelle that contains the cells genetic material (DNA)

• The “brain” of the cell

• Nuclear Envelope: a pair of membranes that surrounds the nucleus

• Nuclear pores: Holes or pores in the nuclear envelope that allow materials to leave the nucleus.

Chromatin

Nucleolus

Pore

Nucleus

Two membranesof nuclear envelope

Roughendoplasmicreticulum

Ribosomes

Ribosome• A small organelle used to change DNA into proteins

• The “assembly line” of the cell

• Made up of proteins and nucleic acids

• Ribosomes are found on the outside of the Endoplasmic Reticulum and others are found floating in the cell.

Ribosome

Smooth ER

Rough ER

Nuclearenvelope

Ribosomes

Endoplasmic Reticulum

An extensive network of membranes that builds cell materials

Two types of Endoplasmic Reticulum

Smooth ER

Rough ER

Nuclearenvelope

Ribosomes

Endoplasmic Reticulum

Rough E.R. Has ribosomes attached to the outside

of the membrane

Creates proteinsSmooth E.R.

Does Not have ribosomes attached to the membrane

Creates enzymes and lipids

Transport vesiclebuds off

Ribosome

Polypeptide

Glycoprotein

Sugarchain

Rough ER

Secretary(glyco-) proteininside trans-port vesicle

Golgi Apparatus

An organelle made up of a series of membrane sacks

Makes changes and directs the materials created by the E.R.

Like a shipping store that packs, directs, and ships materials.

“Receiving” side ofGolgi apparatus

Transportvesiclefrom ER

New vesicleforming

“Shipping”side of Golgiapparatus

Transportvesicle fromthe Golgi

Plasmamembrane

Rough ER

Lysosomes

Transport vesicle(containing inactivehydrolytic enzymes)

Golgiapparatus

Engulfmentof particle

“Food”

Foodvacuole

Digestion

Lysosomeengulfingdamagedorganelle

Vacuole

A large membrane bound sack found inside of the cell

Contractile Vacuole: Used to pump out excess water in cells

Central Vacuole: Stores chemicals and helps plant growth.

LM

650

Centralvacuole

Nucleus

Contractilevacuoles

Nucleus

ChloroplastC

olo

rize

d T

EM

8,7

00

LysosomesMembrane bound sack that contains

digestive enzymes

Lysosomes are used to break down macromolecules Breaks down incoming food Destroy harmful bacteria Recycle damaged organelles

ChloroplastA photosynthetic organelle found

in plant cells

Converts sunlight and CO2 into sugar and oxygen

ChloroplastStroma

Inner and outermembranes

Granum

Intermembranespace

TE

M 9

,750

MitochondriaThe organelle that

creates energy for cells

Uses glucose to create chemical energy (ATP)

Found in plant and animal cells

Creation of energy happens on the membranes inside of the mitochondria

Mitochondrion

Intermembranespace

Outermembrane

Innermembrane

Cristae

Matrix

CytoplasmThe entire region between the nucleus and plasma membrane

A fluid filled space

Flagella and Cilia

Flagella: a long, thin, whip-like structure

Created with microtubules that allow a cell to move

Cilia: smaller, and more numerous hair-like structures

Created with bundles of microtubules

Outer microtubuledoublet

Centralmicrotubules

Radial spoke

Dynein arms

Plasmamembrane

FlagellumElectron micrographsof cross sections:

Flagellum

Basal body

TE

M 2

06,5

00

Basal body(structurallyidentical tocentriole)

TE

M 2

06,5

00

Plasma Membrane

A thin outer layer of a cell

Regulates the flow of molecules into and out of the cell

Made up of a Phospholipid bilayer with membrane proteins, cholesterol, and carbohydrates embedded.

Outer microtubuledoublet

Centralmicrotubules

Radial spoke

Dynein arms

Plasmamembrane

FlagellumElectron micrographsof cross sections:

Flagellum

Basal body

TE

M 2

06,5

00

Basal body(structurallyidentical tocentriole)

TE

M 2

06,5

00

Cell Wall

A strong layer outside of the plasma membrane, used to maintain shape in plant cells

Cell wall is found only in certain bacteria and plant cells.