cells of different organisms and even cells within the same organism are very diverse in terms of...

Cell Diversity

Cell Diversity Cells of different

organisms and even cells within the same organism are VERY diverse in terms of shape, size, and internal organization.

There are at least 200 different types of cells, ranging from flat cells to branching cells to round cells to rectangular cells!

Recurring Theme

One major theme in biology that occurs again and again is that form follows function!

In other words, a cells function influences its physical features.

Cell Shape

The diversity in cell shapes reflects the different functions of the cells

Compare the cells below. How does the nerve cell’s shape help it? The skin cell’s?

Cell Size

Cells differ in their size as well as their shape

Some nerve cells that extend from a giraffe’s spinal cord to the foot can be 2 m long!

Most cells are about 1/500th the size of the period at the end of a sentence.

Cell Size

The size of a cell is limited by the relationship of the cell’s outer surface are to its volume aka surface area-to-volume ratio

Cell Volume As a cell grows, the volume increases much

faster than the surface area

Important because the materials needed by a cell and the wastes produced must pass in and out of the cell through its surface

If a cell were to become very large, the volume would increase more than the surface area, so materials wouldn’t be able to enter or leave quickly enough

Cell Volume

Basic Parts of A Cell

Plasma Membrane

Cytoplasm

Control Center

Plasma Membrane

The cell’s outer boundary

Covers cell’s surface and acts as a boundary

Cannot be seen through a light microscope

Cytoplasm The region of the cell that

is within the plasma membrane and includes the fluid, the cytoskeleton, and all of the organelles

The cytosol is the part of the cytoplasm that includes molecules and small particles, but not membrane bound organelle

Control Center

Cells carry coded information in the form of DNA for regulating functions and reproducing themselves.

Some DNA floats freely in cells, other cells have a nucleus housing the DNA

Nucleus is a membrane-bound structure

Two Basic Cell Types

Prokaryotes Lack membrane bound organelles Have a nucleoid region where DNA

is located Bacteria and Archaea

Eukaryotes Organisms made up of one or more

cells and have membrane bound organelles

Much larger than prokaryotic cells

Prokaryotic Cell

Eukaryotic Cell

Cellular Organization

In multicellular organisms, cells organize into tissues, which organize into organs, then organ systems

Colonial organisms (colonies) are a groups of identical cells that live together in a connected group. These aren’t multicellular because their activities aren’t coordinated

Animal Cell

Nucleus

Nucleolus

Cell Membrane

Cytoplasm

Eukaryotic Cell Organelles and Function

1. Nucleus Nickname: “The Control Center” Function: holds the DNA Parts:

1. Nucleolus: dark spot in the middle of the nucleus that helps make ribosomes

Animal Cell

Nucleus

Nucleolus Ribosomes

Cell Membrane

Cytoplasm

Eukaryotic Cell Organelles and Function

2. Ribosomes Function: makes proteins Found in all cells, prokaryotic and

eukaryotic

Eukaryotic Cell Organelles and Function

3. Endoplasmic Reticulum (ER) Nickname: “Roads” Function: The internal delivery

system of the cell

Animal Cell

Nucleus

Nucleolus

Rough Endoplasmic Reticulum

Smooth Endoplasmic Reticulum

Cell Membrane

Cytoplasm

Ribosomes

Endoplasmic Reticulum

2 Types:1. Rough ER:

Rough appearance because it has ribosomes

Function: helps make proteins, that’s why it has ribosomes

2. Smooth ER: NO ribosomes Function: makes fats or lipids

Animal Cell

Nucleus

Nucleolus

Rough Endoplasmic Reticulum

Smooth Endoplasmic Reticulum

Ribosomes

Golgi Complex

Cell Membrane

Cytoplasm

Eukaryotic Cell Organelles and Function

4. Golgi Complex Nickname: The shippers Function: packages, modifies, and

transports materials to different location inside/outside of the cell

Appearance: stack of pancakes

Animal Cell

Nucleus

Nucleolus

Rough Endoplasmic Reticulum

Smooth Endoplasmic Reticulum

Ribosomes

Golgi Bodies

Cell Membrane

Cytoplasm

Eukaryotic Cell Organelles and Function

5. Lysosomes: circular, but bigger than ribosomes)

Nickname: “Clean-up Crews” Function: to break down food into

particles the rest of the cell can use and to destroy old cells

Animal Cell

Nucleus

Nucleolus

Rough Endoplasmic Reticulum

Smooth Endoplasmic Reticulum

Ribosomes

Golgi Bodies

Mitochondria

Cell Membrane

Cytoplasm

Eukaryotic Cell Organelles and Function

6. Mitochondria Nickname: “The Powerhouse” Function: Energy formation

Breaks down food to make ATP ATP: is the major fuel for all cell

activities that require energy

Animal Cell

Nucleus

Nucleolus

Rough Endoplasmic Reticulum

Smooth Endoplasmic Reticulum

Ribosomes

Golgi Bodies

Mitochondria

Cell Membrane

Cytoplasm

Now let’s talk about structures only found in PLANT Cells!!

Plant Cell

Cell Membrane

Vacuole

Eukaryotic Cell Organelles and Function

7. Vacuoles Function: stores water

This is what makes lettuce crisp When there is no water, the plant wilts

Plant Cell

Cell Membrane

Vacuole

Chloroplasts

Eukaryotic Cell Organelles and Function

8. Chloroplasts Function: traps energy from the sun to

produce food for the plant cell Green in color because of chlorophyll,

which is a green pigment

Chloroplasts

Plant Cell

Cell Membrane

Vacuole

Chloroplasts

Cell Wall

Eukaryotic Cell Organelles and Function

9. Cell Wall Function: provides support and

protection to the cell membrane Found outside the cell membrane in

plant cells

Plant Cell

Cell Membrane

Vacuole

Chloroplasts

Cell Wall

Nucleolus

Nucleus

Rough ER

Smooth ER

Golgi Bodies

Mitochondria

Ribosomes

Cytoplasm

Comparing Plant and Animal Cells

Moon

AnimalPlant