Cell TheoryCell Theory

1.All living organisms are made of one or more cells.

2.The cell is the basic organizational unit of life.

3.All cells come from pre-existing cells.

1.All living organisms are made of one or more cells.

2.The cell is the basic organizational unit of life.

3.All cells come from pre-existing cells.

Visualizing Cells

Visualizing Cells

CELL STRUCTUR

ES

CELL STRUCTUR

ES

NUCLEUSNUCLEUS• The control center for all cell

activity“the brain”

Contains genetic DNA• Surrounded by a thin, double

nuclear membrane• Contains thick protoplasm (rich in

protein) called nucleoplasm (contain chromatin materials)

• The control center for all cell activity

“the brain”

Contains genetic DNA• Surrounded by a thin, double

nuclear membrane• Contains thick protoplasm (rich in

protein) called nucleoplasm (contain chromatin materials)

NUCLEOLUSNUCLEOLUS• Found in the nucleus• Takes part in protein synthesis

(makes ribosome)

• Found in the nucleus• Takes part in protein synthesis

(makes ribosome)

CELLULAR MEMBRANECELLULAR

MEMBRANE• Phospholipids bilayer• Keeps all cell structures inside the

cell• Controls what goes in and what

goes out

• Phospholipids bilayer• Keeps all cell structures inside the

cell• Controls what goes in and what

goes out

NUCLEAR MEMBRANENUCLEAR

MEMBRANE• separates the nuclear material

from other parts of the cell• Not really a solid barrier • semi permeable – allows some

things in and some things out

• separates the nuclear material from other parts of the cell

• Not really a solid barrier • semi permeable – allows some

things in and some things out

CYTOPLASMCYTOPLASM

• Cell materials outside nucleus make up cytoplasm

• CLEAR THICK JELLY LIKE FLUID

• Largest component of cell and holds things in place

• Cell materials outside nucleus make up cytoplasm

• CLEAR THICK JELLY LIKE FLUID

• Largest component of cell and holds things in place

CYTOPLASM HOLDS SEVERAL ORGANIZED STRUCTURES IN PLACE IN THE CELL

THESE STRUCTURES ARE CALLED:

CYTOPLASM HOLDS SEVERAL ORGANIZED STRUCTURES IN PLACE IN THE CELL

THESE STRUCTURES ARE CALLED:

Each organelle has its own specific role.......

“Little Organs”

Endoplasmic ReticulumEndoplasmic Reticulum

• Fastens to cell membrane and nuclear membrane

• Carries materials (nutrients, proteins) through the cell

• Series of canals or channels (pathways) within the cell

• Can be eitherA) SMOOTH ER B) ROUGH ER

• Fastens to cell membrane and nuclear membrane

• Carries materials (nutrients, proteins) through the cell

• Series of canals or channels (pathways) within the cell

• Can be eitherA) SMOOTH ER B) ROUGH ER

RIBOSOMESRIBOSOMES- Small bumps on ER or on cytoplasm - Tiny grainy structures- Small bumps on ER or on cytoplasm - Tiny grainy structures

-Contain enzymes that control PROTEIN SYNTHESIS- Builds protein essential for cell growth and reproduction

-Called protein factories of the cell

MITOCHONDRIAMITOCHONDRIA**Center for respiration in the cell**Releases energy

POWERHOUSE OF CELL

**Center for respiration in the cell**Releases energy

POWERHOUSE OF CELL

At least 95% of energy in cell

comes from mitochondria

Cristea- inward folds…increasesessurface area

Lysosomes(suicide sacs)

Lysosomes(suicide sacs)

• Only one simple membrane• Contains enzymes that cause

digestion of proteins• Breaks down molecules so they

can be used for building materials

• Only one simple membrane• Contains enzymes that cause

digestion of proteins• Breaks down molecules so they

can be used for building materials

Lysosomes will burst open and break down any dead cells

Several hundred lysosomal structures can be seen in the

above phase micrograph.

Several hundred lysosomal structures can be seen in the

above phase micrograph.

GOLGI APPARATUSGOLGI APPARATUS

Looks likes stacks of flattened sacs piled up on one another….

Looks likes stacks of flattened sacs piled up on one another….

These packages then go to the cells surface for export!!! Recieves protein from

endoplasmic reticulum

VacuoleVacuole

• Not considered to be an organelle• Often found in plants (very large)

• Not considered to be an organelle• Often found in plants (very large)

Fluid-filled space that contains water sugar minerals and proteins

PlastidsPlastids Found in plants Some store foods, others act as a

chemical factory

Types: Chloroplasts – contain green pigment called

chlorophyll - traps energy from the sun to make

glucose in photosynthesisLeucoplasts – serve as food storehouses

main center for storing starch

Found in plants Some store foods, others act as a

chemical factory

Types: Chloroplasts – contain green pigment called

chlorophyll - traps energy from the sun to make

glucose in photosynthesisLeucoplasts – serve as food storehouses

main center for storing starch

Onion tip root

CytoskeletonCytoskeleton• Network of protein fibers supporting cell

shape and anchoring organelles• Network of protein fibers supporting cell

shape and anchoring organelles

Actin

Microtubules

Intermediate filaments

Interactive cell siteInteractive cell site

http://www.cellsalive.com/cells/animcell.htm

http://www.cellsalive.com/cells/animcell.htm