Download Chapter 3 Cells, Tissues, and Organ Systems

Chapter 3
Cells, Tissues, and Organ Systems
I. Cell theory
A. Cells
1. Basic units of structure and function of living things
2. Unable to be seen with the unaided eye
B. Organelles
1. Tiny cell structures
2. Discovered by Robert Hooke
C. Theory
1. All living things are made up of cells
2. Cells are basic units of structure and function
3. Living cells come only from other living cells
II. Structure and function
A. Cell wall
1. Made of cellulose, a nonliving material
2. Allows water, oxygen, carbon dioxide and certain dissolved
materials to pass through
3. Found only in plant cells
4. Provides support and protection
B. Cell membrane
1. Thin, flexible envelope that surrounds the cell
2. Allows cells to change shape under pressure
3. Keeps protoplasm of cell separate from outside environment
4. Helps control movement of materials into and out of cell
C. Nucleus
1. Controls all cell activities
2. Contains nucleic acids (large, complex molecules)
a. DNA - stores information needed to build proteins
b. RNA - guides protein making process
3. Surrounded by nuclear membrane
a. Separates nucleus from rest of cell
b. Contains small openings to allow materials to pass into
and out of nucleus
4. Chromosomes
a. Large, irregular mass of thin threads
b. Made of DNA
c. Direct cell’s activities
d. Pass on traits of cell to new cells
5. Nucleolus
a. Little nucleus
b. Made up of RNA and protein
c. Plays important role in making some of cell’s RNA
D. Endoplasmic reticulum
1. Maze of tubular passageways
2. Lead out from nuclear membrane
3. Involved in transport of proteins
E. Ribosomes
1. Grainlike bodies
2. Made up mainly of nucleic acid RNA
3. Protein-making sites of cell
4. Some attached to endoplasmic reticulum
5. Some float freely in cytoplasm
F. Mitochondria
1. Rod-shaped structures
2. Powerhouses of cell
3. Supply energy for cell
G.Vacuoles
1. Large, round, water-filled sacs
2. Float in cytoplasm
3. Storage tanks
a. Food and other materials
b. Waste products can be stored
H. Lyposomes
1. Small, round structures
2. Contain enzymes that break down large food molecules
I. Chloroplasts
1. Large, irregularly shaped green structures
2. Contain chlorophyll
a. Green pigment
b. Captures energy of sunlight
c. Makes food
3. Found only in plant cells
III. Cell processes
A. Metabolism
1. The sum of all building up and breaking down activities in a
living cell
2. Stored energy in food is freed
3. Energy is used to do work
B. Cell Resperation
1. Process by which a cell releases energy from food
2. Two types of respiration
a. Aerobic
i. Food is broken down with the help of oxygen
ii. Water (H2O) and carbon dioxide (CO2) are
produced
iii. Energy is stored in ATP
b. Anaerobic
i. Energy is released
ii. ATP is produced without oxygen
IV.
C. Diffusion
1. Process by which food molecules, oxygen, water and other
materials enter and leave the cell
2. Movement of molecules from a higher concentration to an area
where there is a lower concentration of them
D. Osmosis
1. A special type of diffusion
2. Water passes through cell membrane by osmosis
3. Not enough water, cell dries up
4. Too much water, cell bursts
E. Active Transport
1. Requires energy from cell
2. Special transport of molecules to pick up substance
a. Calcium
b. Potassium
c. Sodium
3. Material carried into and out of cell
Cell growth and division
A. Limits on growth
1. Materials could not enter fast enough
2. Waste products could not leave fast enough
3. Cell would die
B. Cell division
1. Increase in total number of cells
2. Occurs in stages or phases
3. Two types of cell division
a. Meiosis
b. Mitosis
4. Cell division for mitosis
a. Interphase
1). Chromosomes are duplicated
2). Chromatids become attached at centromere
b. Prophase
1). Centrioles move to opposite ends
2). Spindles form
3). Nuclear membrane disappears
4). Nucleolus disappears
c. Metaphase
1). Chromosome pairs line up along the middle of the
cell
2). Attached to spindles
d. Anaphase
1). Chromosomes split apart
2). Move to opposite ends of cell
e. Telophase
1). Nuclear membrane forms around chromatin at each end
2). Nucleolus reappears
f. Cytokinesis
1). Cytoplasm divides into 2 halves
2). Cell membrane forms between two new cells
IV. Organization of living things
A. Division of labor
1. Work of keeping organism alive
2. Divided among different parts of body
B. Five basic levels of organization
1. Cells - level one
a. One-celled organisms
b. Multicellular organisms
2. Tissues - level two
a. Cells that are similar in structure and function
b. Tissue cells carry on activities to keep cell alive
c. Perform one or more specialized function in organism’s body
3. Organs - level three
a. Groups of different tissues working together
b. Each tissue does a special job
4. Organ systems - level four
a. A group of organs that work together to perform certain functions
b. Organs in a system may vary in number and complexity
5. Organisms - level five
a. An entire living thing that carries out all basic life functions
b. Highest level of organization of living things
c. Combination of organ systems
d. Each level of organization interacts with every other level