What the Cell?

Cell

Cell - smallest, independent unit of life!

- made up of organelles – nucleus, mitochondria, cell membrane, etc.

1. Plasma Membrane

Cell Membrane – surrounds the entire cell.

- “Semi-permeable” – lets only certain materials into and out of cell.

- Lipid “Bilayer” -

2 layers of lipids.

ProteinsLipids

Receptors

2. Cytoplasm

Cytoplasm – fluid “jelly” material that fills the cell.

- made up mostly of water!

3. Nucleus

Nucleus – controls all activities of the cell.

- contains chromosomes & DNA.

- in charge of cell divisionNucleus

4. Mitochondria

Mitochondria – makes the cell’s ATP (energy).

- Carries out Cellular Respiration.

5. Endoplasmic Reticulum

E.R. – pathways which transport and make materials.

- Rough ER – has ribosomes.

- Smooth ER – no ribosomes.

6. Ribosome

Ribosome – synthesizes proteins for the cell.

- can be attached to Endoplasmic Reticulum

or “free” floating in the cytoplasm.

7. Vacuole

Vacuole – “sack” that stores materials.

a. Food vacuole – stores food

b. Contractile vacuole – pumps water out

8. Golgi Bodies

Golgi Bodies – package and ship materials around cell.

9. Lysosome

Lysosome – “sack” containing digestive enzymes.

- destroys wastes, food, bacteria, etc.

Plant Cells Vs. Animal Cells

Plant Cells

1. Cell wall – provide support and protection for the cell.

- lies OUTSIDE cell membrane.

- makes plant cells box or diamond shaped.

Cell wall “outer layer”

2. Chloroplast – uses energy from the sun to make simple sugars (glucose).

- contain chlorophyll which captures sunlight.

- carries out photosynthesis:

6H2O + 6CO2 ------> C6H12O6 + 6O2

(water) (carbon dioxide) (glucose)

(oxygen)

3. Central (Large) Vacuole – large vacuole found in the center of most plant cells.

- stores water and sap (food).

Animal Cells

1. Centriole – cylindrical “sticks” that help in cellular division.

2. Small Vacuoles – small storage vesicles found throughout the animal cell.

- animal cells tend to have many small vacuoles to store food, water, or wastes.

Small Vacuole

Single-Celled Vs. Multicellular

Single-cell – organisms that are made of only one cell.

- capable of metabolism and homeostasis.

Ex: bacteria, paramecium, etc.

Multicellular – organisms that are made up of many, many cells.- Tissues – group of cells working together.- Organs – group of tissues working together. (Ex: Stomach)-Organ systems – group of organs working together. (Ex: Digestive)

Ex: Humans, plants, animals

Multicellular Organization

Organelles

Cells

Tissues

Organs

Organ Systems

Organism

Microscopy and Cell TheoryMicroscopy and Cell Theory

- allows light to pass through specimen and uses two lenses to form an image.

- paves the way for cell theory.

- can observe LIVING specimens.

Compound Light Microscope

Electron Microscope• Observe specimens 1000X smaller than

light microscopes.

- uses a beam of electrons.

- can NOT observe living specimens.

Cell Theory

Cell Theory:

1. All living things are composed of cells.

2. Cells are basic units of structure and function in living things.

3. All cells arise from previous cells.