Download Chapter 1 Section 2 - Revere Local Schools

Chapter 1 Section 2 Notes
Looking Inside Cells
Organelles are tiny structures inside cells that have specific functions. Similar to organs in your
body.
a. Cell Wall
i. A rigid layer of nonliving material that surrounds the cell
ii. Made of cellulose, the most abundant carbohydrate on Earth
iii. Animals do not have cell walls
iv. Protects and supports the cell
v. Water, oxygen, proteins, etc can pass through cell walls
b. Cell Membrane
i. Located just inside the cell wall
ii. Controls what enters and leaves the cell (selectively permeable)
iii. Protects the cell by keeping harmful materials out
iv. Bi-layer of phospholipids
2.
The Nucleus
a. The nucleus is the control center of the cell, the brain of the cell
b. Nuclear envelope
i. The nucleus has its own special membrane called the nuclear envelope
ii. Materials pass into and out of the nucleus through nuclear pores, small
holes in the membrane
c.
Chromatin
i. The DNA is found in the nucleus as long, threadlike strands called
chromatin
ii. The chromatin tells the cell what to do, it is the actual controller in the
control room (RNA)
d. Nucleolus
i. Small, dense region inside the nucleus
ii. Makes ribosomes
3.
Organelles in the Cytoplasm
a. The cytoplasm is the region between the cell membrane and the nucleus
i. Regulates temperature
ii. Protects the organelles
iii. Helps with chemical reactions
iv. Gives the cell it’s shape
b. Mitochondria
i. The cell’s powerhouse
ii. Convert food molecules (glucose) to energy w/ the oxygen
c.
Endoplasmic Reticulum
i. A series of pathways and tubes that carry proteins from one region of the
cell to another
ii. The internal transport system of the cell
iii. Two types Smooth and Rough
d. Ribosomes
i. Ribosomes are small organelles that can be found floating in the
cytoplasm or attached to the ER
ii. They are small “factories” that make proteins w/Rna from the nucleolus
e. Golgi Bodies (Apparatus)
i. Look like a stack of flattened stacks
ii. Receive proteins & other materials from ER & package for redistribution
iii. The FedEx of the cell, can ship materials to other parts of the cell or to
other cells
f.
Chloroplasts
i. Found only in plant cells
ii. Capture energy from the sun and convert it into chemical energy
(glucose) through photosynthesis
g. Vacuoles
i. Storage organelles
ii. Plant cells usually have one large vacuole
h. Lysosomes
i. Small organelles containing enzymes and other chemicals
ii. Break down food, wastes, old organelles, etc
iii. Can kill the cell when needed
4.
Specialized cells
a. Cells become specialized in multicellular organisms
b. Stem cells are cells that have not yet specialized & can become any type of cell
c.
5.
Nerve cells, skin cells, bone cells, etc
Bacterial cells
a. Smaller than plant, animal, fungal, or protist cells
b. Do not have a nucleus
6.
Cells with a nucleus are called Eukaryotic Cells
7.
Cells with no nucleus are called Prokaryotic Cells