CELLS Cell The basic unit of life for

CELLS

Cell • The basic unit of life for all living organisms

Cell Theory • All living things are composed of cells • Cells are the smallest functional part of a living organism • All cells come from other cells

CELL TYPES • Cells are either PROKARYOTIC or EUKARYOTIC

Prokaryotic cells • Eubacteria and Archeabacteria • Evolved before eukaryotic cells • No formal nucleus or membrane bound organelles • Structure – Nuclear region, contains one single DNA molecule arranged in a circular chromosome – Ribosomes – Cell membrane – Cell wall (different than plants) – Some have capsules outside wall – Some have pilli or flagella

Bacteria

Eukaryotic cells • Have nucleus and membrane bound organelles • Plasma membrane • Cytoplasm - everything between plasma membrane and nucleus

EUKARYOTIC CELLS ANIMAL PLANT

Cell the basic unit of life for all organisms Cell Organelle A minute membrane bound structure within a plant or animal cell that has a particular job or function.

Nucleus Structure: central membrane bound organelle, contains most of cell’s DNA with its coded instructions to make protein and other molecules. Function: manages or controls cellular function EOC significance: Eukaryotic cells contain a nucleus; prokaryotic cells lack a nucleus.

PLASMA MEMBRANE (cell membrane) • Structure: phospholipid and protein bilayer separating cell from its environment. • Function: Selectively permeable-regulates enter and exit of materials. • EOC significance: Allows for homeostasis within cell.

PLASMA MEMBRANE cholesterol carbohydrate chains cytoskeleton phospholipid Channel protein

Structure: A fairly rigid structure made of cellulose. Present in plants, fungi, most bacteria, and some protists. Function: Provides support and protection, gives the shape of the cell. Cell Walls

Mitochondria Structure: 2 nd membrane is folded inside 1 st membrane. Function: Sources of energy, transform energy stored in food molecules to ATP (useable energy). Powerhouse-most numerous in cells needing most energy-muscle cells. Replicates itself. EOC significance: The folded inner membrane increases the surface area in order to create more useable energy.

VACUOLE Structure: membrane bound sac-like organelles in the cytoplasm. Function: temporarily stores water and substances dissolved in water that is important to the cell. Significance: Plant vacuoles are larger than animal vacuoles

Some protista cell vacuoles pump water out by contracting: FIND 2 Contractile vacuoles in this Paramecium?

Chloroplasts Structure: organelle with stacked membranes that contain chlorophyll (green pigment) in plants. Function: Site of photosynthesis where light energy is converted to chemical energy (glucose). EOC significance: stacked membranes allow more surface area for maximum production of chemical energy (glucose)

Ribosomes Structure: Looks like small dot, made of ribonucleic acid. Function: Proteins are made on its surface. EOC Significance: Most important job of the cell is to make proteins (no ribosomes = no life)

Animal vs Plant Cell • Animal cells - Roundish – centrioles (important in cell division) • Plant cells - Rectangular – – Large permanent central vacuole Cellulose cell wall Chloroplasts Other organelles are common to both

Hierarchy of Cell Organization • • • 1. Cell 2. Tissue 3. Organ 4. Organ system 5. Organism

Cells are organized into different types of TISSUE Group of cells that carry out a common function. - muscles - motion - bones – support - nerves - coordination, perception and automatic body functions

ORGAN Several tissues working as a unit animal heart brain stomach plant stem trunk leaf

ORGAN SYSTEM Many organs involved in carrying out a function • digestive • nervous • skeletal • excretory • respiratory • endocrine • circulatory • muscular • reproductive • integumentary

ORGANISM Complete living thing cell tissue organ system organism

CELL SPECIALIZATION • Different kinds of cells suited for a different activity.

DIVISION OF LABOR • Different cells divide their labor each has a specific function and supports each other. – Design and shape of a cell relates to its function and conditions under which it works.

• Unicellular organisms tend to have fairly complex cells, which makes sense considering that these organisms must depend on only one cell to do everything. • Multicellular organisms have greater specialization:

Red Blood Cells Structure: Smooth, disk-like flattened membranes Function: To deliver oxygen to tissue. (Short lived and do not contain most other organelles, including nuclei —too expensive). Connection: Flattened for maximum amount of surface area while still remaining smooth enough to slide through the smallest capillaries. Structure relates to

Nerve Cell Structure: Very long with branches. Function: Responsible for the rapid conduction of messages throughout the body by connecting to other nerve cells branch to branch. Significance: Form relates to function.

Muscle Cells Structure: A lot of mitochondria and microfibers because they generate large amounts of force (need ATP for energy) Significance: Form relates to function.

IT’S OVER THE END IS HERE!!!