Energy, Enzymes, OH MY

Energy, Membrane and
Enzymes, Oh My

BIO 110

Cell Membrane

• Regulates what can and can’t enter the cell.

• Phospholipid bilayer (heads = hydrophilic; tales = hydrophobic)

• Contains:

- Cholesterol: maintains membrane fluidity

- Proteins: many purposes (anchor, transport, cell signaling)
- Glycolipids and glycoproteins : cell recognition, immunity

Image Source: Wikimedia Commons

Multiple Choice

Which of the following is responsible for getting large or charged (polar) molecules across the cell membrane?

• E
• B
• C
• D

Multiple Choice

The cell membrane is selectively permeable, which means...

• All materials can enter and leave the cell
• Certain things can enter while others cannot
• The cell manually sorts through all materials
• Only certain cells can interact with the cell.

Labelling

Move these labels to the correct place

Drag labels to their correct position on the image

Hydrophobic side

Hydrophilic side

Energy

• Capacity for doing work

• Many types of energy, including:

- Kinetic: energy in motion

- Potential: stored energy due to its position

- Thermal: usually in the form of heat

- Chemical: energy released or stored in chemical bonds/reactions

Image Source: Wikimedia Commons

Match

Match the following

• Kinetic Energy

• Potential Energy

• Thermal Energy

• Chemical Energy

Motion

Stored energy

Heat energy

Chemical bond/reactions energy

• Motion

• Stored energy

• Heat energy

• Chemical bond/reactions energy

Transport across membranes

• Passive transport requires no energy.

- Substances move along a concentration gradient from high to low

• Active transport requires energy.

- Substances move against a concentration gradient from high to low

Image Source: Wikimedia Commons

Transport across membranes

Passive Transport

Active Transport

Simple Diffusion

Pumps/Carrier Proteins

Facilitated Diffusion

Endocytosis

Osmosis

Exocytosis

Diffusion

• Diffusion is the passive

movement of molecules in favor of their concentration gradient (from high concentrations to low concentrations)

Image Source: Wikimedia Commons

Lower concentration

Higher concentration

1. Passive Transport: Simple Diffusion

• Simple diffusion is diffusion through the plasma membrane without aid

Who can do this?:

- Oxygen

- Carbon dioxide

- Ethanol

- Urea

-Water

Image Source: Wikimedia Commons

2. Passive Transport: Facilitated diffusion

• Facilitated diffusion is still diffusion but utilizing a channel protein

Who can do this?:

- Large substances

- Polar molecules

- Glucose

- Ions

Image Source: Wikimedia Commons

3. Passive Transport: Osmosis

• Osmosis is diffusion of water to dilute solutions

Image Source: Wikimedia Commons

Tonicity

• Tonicity describes the

amount of solute in a

solution in relation to

a cell

- Isotonic: amount of solutes in and out of the cell is equal

- Hypotonic: amount of solutes in the solution is less than inside the cell

- Hypertonic: amount of solutes in the solution is greater than inside the cell

Image Source: Wikimedia Commons

Tonicity

Image Source: Wikimedia Commons

Match

Match the following

• Simple Diffusion

• Facilitated diffusion

• Osmosis

High to low conc. without aid

Diffusion using channel proteins

Diffusion of water

• High to low conc. without aid

• Diffusion using channel proteins

• Diffusion of water

4. Active Transport: Pumps/Carrier
Proteins

• Used to move molecules against their concentration gradient

Sodium/Potassium Pump
Image Source: Wikimedia Commons

5. Active Transport: Endocytosis

• Uses vesicles to move large molecules, cells, or large quantities into the cell

Image Source: Wikimedia Commons

6. Active Transport: Exocytosis

• Uses vesicles to move large molecules, or large quantities out of the cell

Image Source: Wikimedia Commons

Categorize

Options (12)

Requires energy

Requires no energy

Exocytosis

Pumps

Goes from low to high concentrations

Diffusion

Osmosis

Goes from high to low concentrations

Less solutes in solution than in cell

More solutes in the solution than in the cell

Organize these options into the right categories

Active Transport

Passive Transport

Hypotonic

Hypertonic

Metabolism

• Sum of all chemical reactions in an organism

Metabolism = anabolism + catabolism

Image Source: Wikimedia Commons

Enzymes

• Substance that speeds up chemical energy and lowers activation energy.

• Enzymes are unique to their substrate; form enzyme-substrate complex.

Image Source: Wikimedia Commons and Amoeba Sisters

Enzymes are affected by:

•pH and temperature:
- Enzymes have an ideal range; anything too far outside of it can cause denaturation

• Cofactors and coenzymes

- help an enzyme function properly

• Inhibitors

- Molecules that can reduce or stop enzyme activity

Multiple Choice

In the diagram, what is letter A? 

• product
• substrate
• enzyme-substrate complex
• active site

Multiple Choice

Letter B...

• active site
• enzyme
• substrate
• products

Multiple Choice

Letter D...

• active site
• enzyme
• substrate
• products

Multiple Choice

Letter C...

• active site
• enzymes
• substrate
• products