The study of cells

All living things are composed of cells

Cells are basic units of life

New cells come from pre-existing cells

BUT….

How did the very first cell get here????

Viruses lack typical cell structure, use host cells to reproduce

Mitochondria and chloroplasts have their own genetic material/can reproduce independent of cell

Small

No NucleusNo membrane bound organelles

Bacteria

Then what do they have?Cell membraneCytoplasm

Ribosomes

DNA: Circular, not in nucleus

Simple

Prokaryotic Structure

DNA

cytoplasm with ribosomes

cell membrane

More complexLarger

Contain membrane bound organelles

Specialized compartment with a specific function

DNA in nucleus in long strandsPlant cells

Animal cells

Fungi (Yeast)

Cytoplasm (protoplasm):

The fluid inside a cell, but outside the nucleus

Cyclosis:

Streaming movement of cytoplasm

Oh where, oh where do we find cell organelles?

“Holds” organelles in place

Site of cellular chemical reactionschemical reactions

Cytoplasm

Cytoplasm

Controls cell processesContains hereditary information (DNA)

Nucleolus: Ribosome formation

Nucleus:

Nucleus

Nucleus

Nucleolus

Nucleolus

Mitochondria

Outer and inner membranesRelease energy from food to make useable energy (ATP)

Animal cellsPlant cells

Contain their own DNA!

Inner membrane folded

(Increased surface area)

Found in:

Mitochondria

Mitochondria

Chloroplasts

Site of photosynthesis

Only in plant cells

Convert light energy to chemical bond energy

Contain their own DNA!

Chloroplasts

Animal cells don’thave

chloroplasts!!!

Ribosomes

Site of protein synthesis

Can be free in cytoplasm or attached to endoplasmic reticulum

Ribosomes

Ribosomes

Endoplasmic reticulum

“ER”

Assembles components of cell membrane

Protein modification

A system of membranous sacs

Rough endoplasmic reticulum

Protein synthesis

Rough: Ribosomes

Smooth endoplasmic reticulum

Smooth: No ribosomes

Contains enzymes needed for cell

Ex. enzymes for lipid synthesis

RER

SER

Smooth ER

Smooth ER

Rough ER

Rough ER

Marks proteins for use in cell or export (adds address w/proteins)

Produces digestive enzymes

Golgi Who? Golgi Who? apparatus, complex, bodiesapparatus, complex, bodies

Golgi body

Golgi body

DNA instructions forbuilding proteinchains leave the nucleusand enter the cytoplasm.

assorted vesicles

Golgibody

smooth ER

rough ER

Chains are assembled on ribosomes in cytoplasm.

Lysosome

Packaged by Golgi body

Membranous sac filled with digestive enzymes

“Suicide Sacs”

Lysosomes

Lysosome

Lysosome

Vacuole

Cell storage:

WaterFoodWastes

Plants: One large central vacuole

Animals: Few small vacuoles

Vacuoles are crucial in single-celled organisms to Vacuoles are crucial in single-celled organisms to maintain homeostasismaintain homeostasis

Vacuole

Cell Wall

Provides support

Provides shape

Made up mostly of cellulose

Animal cells don’t have!

Cell wall

Animal cellsdon’t havecell walls!!!

Centriole

Used in cell division

Animal cells only

Centriole

Plant cellsdon’t havecentrioles!!!

Cilia:

Flagella:

Locomotion

Moving substances across surface of cell

Locomotion

Cilia

Plasma membrane/cell membrane

Plant AND animal cells

Controls what goes in and out of cell

Protection

Support

Cellmembrane

Cellmembrane

• Main component of cell membranes

Lipid Bilayer

lipid bilayer

fluid fluid

Cell (Plasma) Membrane Structure

☼ 2 layers of phospholipids (lipids with phosphate groups attached)

☼ Proteins - embedded in lipid layers- for transport or receptors

☼ Carbohydrates - attached to surface proteins or lipids – markers

☼ Lipids & Proteins can move along membrane = “Fluid”

FLUID MOSAIC MODEL of Cell Membrane

Receptors recognize substances (hormones etc.)and allow them to enter cell

Animal Cells Plant Cells

Cell Walls

Chloroplasts

Centrioles

Golgi Bodies

Vacuoles

NO YES

YES

NO

NO

1 or 2 100 +

YES

Many Small Few Large

Cell wall

Cellmembrane

Vacuole

Mitochondria

Ribosomes

Golgi body

Nucleus

Nucleolus

Smooth endoplasmicreticulum

Cytoplasm

Rough endoplasmicreticulum

Lysosome

Chloroplasts

Golgi body

Smooth endoplasmicreticulum

Nucleolus

NucleusCytoplasm

Rough endoplasmicreticulum

Mitochondria

Free ribosomes

Lysosomes

Centrioles

Cell membrane

Cilia

Methylene blue

Staining TechniquesApplying stain makes cell structures more visible

Can be useful in identifying organisms

Example:

Organelle

Cell

Tissue

Organ

Organ System

Organism