Honors Bio Unit 2

What are the 3 parts of cell theory?

1. All living things are made up of cells

2. Cells are the basic units of structure and function in living things. 

3. New cells are produced from existing cells. 

The smallest basic unit of any organism is the…?

cell

How many cells make up the human body?

50-100 trillion

What is a cell?

The smallest, basic unit of life

Eukaryotic Cells 

1. often contains dozens of structures and internal membranes

2. nucleus separates genetic material from the rest of the cell

Are humans eukaryotic?

Yes

Prokaryotic cells

1. no internal membrane-bound organelles within their cytoplasm

2. are unicellular

What is the most common prokaryotic cell?

Bacteria and it multiplies rapidly.

Nuclues

1. controls cell processes

2. contains DNA

3. sends out messages to tell the cell to grow, divide, or die

Cytoplasm

1. everything between the nucleus and the cell membrane

2. contains organelles and cytosol

Cytosol

jelly-like fluid in the cell

Cytoskeleton

helps cell maintain correct shape (scaffolding)

Microtubules

works like a conveyor belt to move organelles throughout the cytoplasm

Mitochondria

1. Powerhouse of the cell

2. helps turn food into energy for the cell

Adenosine triphosplate (ATP)

food turned into energy for the cell

Ribosomes

reads RNA and translates it into protein by sticking amino acids in order RNA code defines

Ribosomes can be thought of

Protein Factories

Endoplasmic Reticulum

creates, folds, modifies, and translates proteins. Has a rough section covered in ribosomes

Golgi Apparatus

items go through packaging and labeling. Once materials leave they are useful inside/outside of the cell. 

The Golgi Apparatus is also known as

“post office of the cell”

Cell Membrane

1. double layer of lipids and proteins that surrounds a cell and separates the cytoplasm from its environment. 

A cell membrane has a _ head _ tail

hydrophilic head and hydrophobic tail

Cell membranes are composed of _

2 phospholipid layers (hydrophilic head and hydrophobic tail)

Fluid Mosaic Model

made up many different molecules (lipids, proteins, carbohydrates) that are easily moved/ pliable

Cell Membranes are _

selectively permeable

What does it mean that the cell membrane is selectively permeable?

only certain substances can come in or out of the cell

What prevents entry to the cell?

1. size of molecules-molecules too big can’t squeeze through the phospholipid bilayer

2. charge of molecules-polar or charged molecules need assistance

Channel Proteins

allows polar/charged compounds to avoid the hydrophobic core of the plasma membrane

What is Aquaporin? 

the water channel

Diffusion

process by which particles of a substance move from areas of higher cconcentration to lower concentration

What is diffusion a force of? 

the driving force behind the movement of materials across the plasma membrane

Concentration Gradiant

difference in number of particles of a substance in two neighboring regions from high to low. 

Examples of concentration gradiant

Oxygen, Glucose, CO2

Why do particles move from high to low concentration?

Particles move in every direction, the side with more particles is more likely to move in one direction to the side with less particles.

Equilibrium is when…

Is when both sides have the same number of particles; each side is just as likely to move on way as the other. 

Materials diffuse until?

equilibrium-net charge of 0

Osmosis-

diffusion of water molecules through a selectively permeable membrane from an area of greater concentration of water to an area of lower concentration

Isotonic

1. solutions in which the concentrations are equal

2. no net water movement=no change in size of the cell

Hypertonic

1. solutions with larger concentrations of water

2. If a cell is placed in a hypertonic solution=water leaves the cell, and the  cell will shrink

hypotonic

1. solution with a lower concentration of solute

2. If a cell is placed in a hypotonic solution=water will enter the cell, and the cell will swell

Facilitated Diffusion

Diffusion of a substance through a transport protein embedded in a membrane

Passive Transport

method that requires no energy to move substances

What are the three examples of passive transport

1. Diffusion 2. Osmosis 3. Facilitated Diffusion

Active Transport

moving particles against the concentration gradient-lower to high concentration

Example of active transport

riding a bike up a hill

Levels of Organization

Arrangement of specialized parts within a living things

Division of Labor

work of keeping the organism alive is divided among different parts, more complex organisms have more work to divide

What is the least complex level of organization? 

The atom

1. Atom

smallest non-living unit needed to build living things

2. Molecule

Atoms joined together via chemical bonds

3. Macromolecules

many molecules joined together to form a large molecule

4. Organelles

macromolecules work together that do different jobs inside cells 

5. Cells

1. building block of living things

2. this is the level where life begins

3. lots of different kinds of cells

6. Tissues

1. rarely work alone in multicellular organisms like humans

2. cells that are similar in structure and function are usually joined together from tissues

7. Organs

when a bunch of different types of tissues work together, they form an organ

How many organs are in the human body?

78 organs

8. Organ system

each organ in your body is a part of an organ system that works together to perform a major function

What is a organ system?

A group of organs

What is the most complex level of organization?

Organ System

What do organ systems create?

They create organisms

What are the 11 organ systems that make us?

1. Circulatory system

2. Digestive

3. Endocrine 

4. Excretory

5. Integumentary 

6. Immune

7. Muscular

8. Nervous

9. Reproductive

10. Respiratory

11. Skeletal