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 Eukaryotes 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 Cytoplasm Nucleolus Nucleus Cell Membrane

Eukaryotic Cell Organelles and Function Nucleus Nickname: “The Control Center” Function: holds the DNA Parts: Nucleolus: dark spot in the middle of the nucleus that helps make ribosomes

Animal Cell Cytoplasm Nucleolus Ribosomes Nucleus Cell Membrane

Eukaryotic Cell Organelles and Function Ribosomes Function: makes proteins Found in all cells, prokaryotic and eukaryotic

Eukaryotic Cell Organelles and Function Endoplasmic Reticulum (ER) Nickname: “Roads” Function: The internal delivery system of the cell

Animal Cell Cytoplasm Nucleolus Ribosomes Nucleus Cell Membrane Smooth Endoplasmic Reticulum Rough Endoplasmic Reticulum

Endoplasmic Reticulum 2 Types: Rough ER: Rough appearance because it has ribosomes Function: helps make proteins, that’s why it has ribosomes Smooth ER: NO ribosomes Function: makes fats or lipids

Animal Cell Cytoplasm Ribosomes Nucleolus Nucleus Cell Membrane Smooth Endoplasmic Reticulum Rough Endoplasmic Reticulum Golgi Complex

Eukaryotic Cell Organelles and Function 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 Cytoplasm Nucleolus Ribosomes Nucleus Cell Membrane Smooth Endoplasmic Reticulum Rough Endoplasmic Reticulum Golgi Bodies

Eukaryotic Cell Organelles and Function 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 Cytoplasm Nucleolus Ribosomes Nucleus Cell Membrane Mitochondria Rough Endoplasmic Reticulum Smooth Endoplasmic Reticulum Golgi Bodies

Eukaryotic Cell Organelles and Function 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 Cytoplasm Nucleolus Ribosomes Nucleus Cell Membrane Mitochondria Rough Endoplasmic Reticulum Smooth Endoplasmic Reticulum Golgi Bodies

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

Plant Cell Vacuole Cell Membrane

Eukaryotic Cell Organelles and Function Vacuoles Function: stores water This is what makes lettuce crisp When there is no water, the plant wilts

Plant Cell Vacuole Chloroplasts Cell Membrane

Eukaryotic Cell Organelles and Function 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 Vacuole Chloroplasts Cell Membrane Cell Wall

Eukaryotic Cell Organelles and Function Cell Wall Function: provides support and protection to the cell membrane Found outside the cell membrane in plant cells

Plant Cell Cytoplasm Vacuole Smooth ER Ribosomes Chloroplasts Cell Membrane Cell Wall Nucleolus Golgi Bodies Nucleus Mitochondria Rough ER

Comparing Plant and Animal Cells Moon Animal Plant