AP Bio - Unit 5 (Part 1)

Plasma Membranes regulate whether certain substances can cross it easily or not

What does selectively permeable mean for plasma membranes?

Transport materials in and out of the cell, intracellular communication, and protection for the cell

What are two benefits (functions) of plasma membranes?

As a mosaic of protein molecules bobbing in a fluid bilayer of phospholipids

How does the Fluid Mosaic Model describe the membrane?

Tails

What parts of phospholipids are hydrophobic and noncharged/nonpolar?

Heads

What parts of phospholipids are hydrophilic and charged/polar?

Cholesterol acts as a glue for the phospholipids and packs it all closely together

How does cholesterol affect movement of phospholipids in high temperatures?

Cholesterol acts as a spacer for phospholipids and creates gaps in the bilayer.

How does cholesterol affect movement of phospholipids in low temperatures?

Free

Are most lipids and some proteins in the membrane bound or free?

Phospholipids

Which moves rapidly: Phospholipids or Proteins?

It means they have polar heads and nonpolar tails

What does it mean when phospholipids are called amphiphilic?

Integral Proteins

What membrane proteins penetrate the hydrophobic interior of the phospholipid bilayer?

Transmembrane Proteins

What are Integral Proteins that span the membrane called?

Peripheral Proteins

What membrane proteins are loosely bound to the surface of the membrane?

Inside of the phospholipid bilayer

Where do the hydrophobic parts of membrane proteins go?

The edges of the phospholipid bilayer

Where do the hydrophilic parts of membrane proteins go?

Transport, Enzymatic Activity, Signal Transduction, Cell to cell Recognition, Intercellular Joining, and attachment to the cytoskeleton

What are the six major functions of membrane proteins?

Glycolipids

What are membrane carbohydrates that covalently bond to lipids called?

Glycoproteins

What are membrane carbohydrates that covalently bond to proteins called?

They're involved in cell to cell recognition

Why are glycolipids and glycoproteins important?

Small, nonpolar, hydrophobic, uncharged

What are characteristics of molecules that pass through the membrane?

Large, polar, hydrophilic, charged

What are characteristics of molecules that pass through embedded channel transport proteins?

Channel Proteins and Carrier Proteins

What are the two types of transport proteins?

Carrier Proteins

Which transport protein binds molecules together and changes shape to shuttle across the membrane?

Channel Proteins

Which transport protein has a hydrophilic channel that certain molecules can use for transport?

Aquaporins

Which channel protein specifically facilitates the transport of water?

Yes

Can small amounts of water pass through the membrane without a protein?

Hypertonic

What is an area with more solutes called?

Hypotonic

What is an area called with less solutes called?

Molarity

What is the measure of how many solutes called?

Isotonic

What is it called when the solute concentration is the same as inside the cell?

Tonicity

What is the ability of a surrounding solution to cause a cell to gain or lose water called?

Hypertonic

What area does water move to: Hypertonic or Hypotonic?

Hypertonic

What type of solution environment would cause a cell to shrink: Hypertonic or Hypotonic?

Hypotonic

What type of solution environment would cause a cell to expand: Hypertonic or Hypotonic?

Plants, prokaryotes, and fungi

What types of cells have cell walls?

Cellulose

What are cell walls composed of?

High

When water flows into a plant cell it will have a ____ turgor pressure

down/with

In passive transport, do molecules move with or against their concentration gradient?

high to low

In passive transport, do molecules from high to low or low to high concentration?

No

In passive transport, is energy needed?

Importing materials and exporting waste

What is the primary role of passive transport?

Osmosis

What is the diffusion of free water across a selectively permeable membrane from high to low concentration until equilibrium is reached called?

Osmoregulation

What is the control of solute concentrations and water balance?

Flaccid

What is another word for a cell that is limp?

Turgid

What is another word for a cell that is firm?

Against

In active transport, do molecules move with or against their concentration gradient?

Low to High

In active transport, do molecules move from high to low or low to high concentration?

Yes

In active transport, is energy needed?

To collect necessary molecules like glucose or amino acids into the cell

What is the primary role of active transport?

Membrane potential

What is the voltage across a membrane?

Sodium-Potassium Pump

What is a common type of active transport system that contributes to membrane potential?

Exocytosis

What is it the process of transport vesicles migrating and fusing to the membrane and then releasing their contents called?

Endocytosis

What is the process called when the cell takes in molecules in order to form new vesicles from the plasma membrane?

Adding the pressure potential and the solute potential together

How is water potential calculated?

Zero

What is the pressure potential of an open container?

-iCRT

How do you calculate solute potential? (write the equation)

Ionization constant

What is i in the solute potential equation?

1

What is the ionization constant for sugar?

2

What is the ionization constant for salt?

Molar concentration

What is C in the solute potential equation?

Pressure constant

What is R in the solute potential equation?

0.0831

What is the pressure constant always equal to?

Temperature

What is T in the solute potential equation?

Kelvin

What is temperature measured in for the solute potential equation?

Add 273

How do you make a celsius number into kelvin for the equation?