Wiki Page, NGSS BIO-A (TRI 1 22-23): Study Guide

Wiki Page
2022-09-21T14:53:48-07:00

1. Characteristics of Life

1. It responds to the environment

2. It grows and develops

3. It produces offspring

4. It maintains homeostasis

5. It has complex chemistry/metabolism

6. It consists of cells

2. Matter and Energy: Matter and Energy cannot be created or destroyed, only transferred/transformed.

3. Cell Organelles and their functions: (NOTE: The functions are not listed here.)

1. Cell Membrane

2. Cytoplasm

3. Nucleus

4. Chromosome

5. Golgi Body

6. Endoplasmic Reticulum

7. Ribosome

8. Lysosome

9. Vacuole

10. Mitochondria

4. Cell Membrane

1. Functions :

1. Separates the contents of the cell from the outside environment

2. Serves as a barrier for which substances can enter and exit a cell

3. Recognizes chemical signals (messages) which will trigger the cell to react in a particular way

2. Selective Permeability

1. That means that some molecules can pass through, and some molecules cannot

2. It maintains balance both inside and outside the cell

3. Structure of the Cell Membrane

1. Made up of a double layer of "phospholipids"

2. Phospholipid is made of two parts

1. Phosphate head (water loving) - outside the membrane

2. Lipid tails (water fearing) - inside the membrane

3. Cholesterol

1. Rigid molecules within the membrane

2. Provide structure to the fluid membrane

3. Prevents fatty acid chains (of the lipid tails) from sticking together

4. Membrane Proteins

1. Embedded within the membrane because most molecules cannot easily pass through the "water fearing" lipid tails

2. Enables molecules to pass through without interacting with the lipids

3. Many types (we talked about 3)

1. Transport (Channel) Proteins

1. Shaped like tubes and form a channel through the cell membrane

2. Only allow certain molecules to pass through

2. Receptor Proteins

1. Communicate information from outside the cell to inside the cell

2. Typically span the membrane and have a portion that sticks out from the cell membrane. When a molecule of the same shape fits into the receptor, it causes a response inside the cell to occur

3. Marker Proteins

1. Acts as an identifier and distinguishes types of cells from each other

2. Referred to as "glycoproteins" (glycol = sugar/glucose)

5. Fluid-Mosaic Model

1. Fluid component - portions of the cell membrane have the ability to move

2. Mosaic portion - lipids and proteins dispersed through the membrane form patterns

6. Passage of Materials through cell membranes

1. Cells need a way to move molecules and other substances through their membranes

2. Some molecules, such as water, pass freely (this is passive transport)

3. Others that do not pass freely must be carried through channels and require ENERGY (this is active transport)

7. Simple Diffusion

1. Movement of molecules from high concentration to low concentration

2. Pass directly through the lipid bilayer without help of channels

3. No energy

4. Examples: oxygen, carbon dioxide

8. Facilitated Diffusion

1. movement of molecules down their concentration gradient with the help of transport proteins embedded within the cell membrane

2. no energy required

3. Example: water, glucose

9. Osmosis

1. Diffusion of water through a membrane

2. High concentration to low concentration

3. No energy

10. Hypotonic solution

1. inside of a cell has a much higher salt (salute) concentration than outside of a cell

2. Water diffuse into the cell to "dilute" the inside contents

3. Result: Cell SWELLS and sometimes bursts

4. Example: Tap Water Gummy Bear

11. Hypertonic Solution

1. outside of cell has a much higher salt (solute) concentration than the inside of a cell

2. water will diffuse out of the cell to "dilute" it's surroundings

3. Result: cell shrivels (shrinks)

4. Example: Salt Water Gummy Bear (if yours worked correctly)

12. Isotonic Solution

1. when the solute concentration outside the cell is equal to the solute concentration inside the cell

2. No net movement of water

13. Osmosis in plan cells

14. Active transport

1. Movement of molecules through a cell membrane from an area of low concentration to an area of high concentration

2. Requires ENERGY

3. Requires transport proteins

4. Types:

1. Endocytosis - cells take in particles

1. Phagocytosis

1. Cell "Eating"

2. Movement of larger food particles across the membrane with the use of pseudopods

2. Pinocytosis

1. Cell "Drinking"

2. Taking in smaller dissolved ions or molecules

2. Exocytosis

1. Cell "excreting"

2. Cell get rid of particles by enclosing them in a vesicle and fusing that membrane with the cell membrane