CELLS!Unit 3 – Lesson 2

Cells• There are many different kinds of

cells, and they do many different things.

• Many organisms live life as a single cell! We say they are unicellular!

• Other organisms are clusters of cells. We say they are multicellular!

ATOMS COMBINE TO MAKE SMALL BASIC UNTIS OF

LIFE!We call these CELLS

Multicellular or Unicellular?

Multicellular Organisms• Multicellular organiams are

ORGANIZED. The cells don’t just float around at random, They work together to make different structures.

CELL TISSUE

ORGAN

ORGAN SYSTEMORGANISM

So, since we are talking about cells…what does the INSIDE of a cell look like? Is it organized

too?

Comparing Cells• Since there are so many

different cells, we categorize them into two types.

• Prokaryotes• Eukaryotes

Prokaryotes• Prokaryotes – lack membrane bound

organelles.

• Examples:– Single-cell organisms– Bacteria

Uhh, what’s a

membrane?

BACTERIA

Eukaryotes• Eukaryotes – cells that contain

membrane bound organelles.

• Examples: • Protists• Fungi• Plants• Animals

Eukaryotes• There are two main types of

eukaryotic cells. – Plant cells– Animal cells

Animal Cell

Plant Cell

ANIMAL CELL

PLANT CELL

Cell Organization

Cell Organization• All life is organized, remember? So cells have tiny

structures that help with their function.

• We call these ORGANELLES!

Looks like

mini-organs!

Cell Wall

• Tough rigid outer coverings that protects the cell and give it shape.

• Found in plants, algae, fungi, and some bacteria.

Animal Cell

Plant Cell

Cell Membrane• Protective layer

around all cells.

• For cells with a cell wall, the cell membrane is inside the cell wall.

• It allows food and oxygen into the cell and waste products out of the cell.

Animal Cell

Plant Cell

Cell (Plasma) MEMBRANE

The pink structure indicates a protein in the cell membrane

Cytoplasm• The “soup” in which

all other organelles reside. A gelatin like mixture.

• Chemical reactions occur within the cytoplasm.

• Holds organelles in place.

Animal Cell

Plant Cell

Nucleus

• Contains the DNA responsible for providing the cell with its unique characteristics.

• Acts as the control center.

• Contains a nucleolus.

Animal Cell

Plant Cell

Chloroplasts• Green organelle that

makes food for a plant.

• Contains chlorophyll.

• Where photosynthesis occurs (photosynthesis allows the plant to make food).

Animal Cell

Plant Cell

CO2H2O

Sugar

Mitochondria

• Provides the energy a cell needs to move, divide, produce secretory products, and contract.

• Where cellular respiration occurs.

Animal Cell

Plant Cell

ENERGY

Sugar O2

Ribosomes

• The site of protein synthesis.– making proteins

for the cell

• Can be found on Rough ER.

Animal Cell

Plant Cell

Endoplasmic Reticulum

• Where cellular materials are processed.

• Smooth ER – when no ribosomes are present.

• Rough ER – when ribosomes are attached.

Animal Cell

Plant Cell

Golgi Bodies• Sort proteins and

other cellular substances and package them into vesicles.

• Vesicles deliver substances to other areas of the cell.

Animal Cell

Plant Cell

Vacuole• Stores water, waste

products, food, and other cellular material.

• In a plant cell, vacuoles are very large! This is because plants need to store more materials.

Animal Cell

Plant Cell

Lysosome• Breaks down food molecules, cell

wastes, and worn out organelles.

Lyse = CutSome = Body

Animal Cell

Plant Cell

LYSOSOME

BACTERIA

BACTERIA

BACTERIA

BACTERIA

BACTERIA

RECYCLED PARTS

RECYCLED PARTS

RECYCLED PARTS

LYSOSOME

Other Organelles• Cells can move using a flagella or cilia.

Animal Cell

Plant Cell