What are the 4 main functions of the plasma (cell) membrane?

Acts as a boundary between interior and exterior of cell and extracellular environment

Control what enters and exits cell

Organizes chemical reactions of the cell

Holds teams of enzymes that function in metabolism

In water, phospholipids from a (blank blank).

Stable Bilayer

Membrane components are amphipathic. Define amphipathic.

Molecules that have hydrophillic and hydrophobic properties.

The cell membrane is a fluid mosaic of (blank) and (blank).

Lipids and proteins

On the cell membrane, lipid molecules form a flexible (blank), protein molecules are (blanked) in the cell membrane, and (blanks) act as cell identification tags on the surface of the membrane.

Bilayer

Embedded

Carbohydrates

What are the six major functions preformed by membrane proteins?

1) maintain cell shape

2) receptors for signalling molecules

3) enzymatic activity

4) cell-cell recognition

5) intercellular junctions

6) transportation

Carbohydrates are found on the (blank) (blank) of cell membrane

Exterior surface

Carbohydrates provide (blank) for cell-cell or cell-protein interactions.

(Blanks) are sugars attached to a lipid

(Blanks) are sugars attached to a protein

Specifity

Glycolipids

Glycoproteins

Cell membrane controls traffic into and out of the cell by being (blank blank).

Selectively permeable

Which kinds of molecules can cross the lipid bilayer? Which ones cannot?

Hydrophobic molecules CAN dissolve in the bilayer and pass through

Hydrophillic molecules and ions do NOT cross the membrane easily

What are the two types of transport proteins? How many types of substances can work with a single protein?

Channels and transporters

only one type of solute per protein

The two main types of passive transport are what, and what differentiates them?

Diffusion and Osmosis. Same idea for both, the spread of high concentration to low concentration, but osmosis is specific to water.

In passive transport, substances (blank) through membranes from areas of (blank) concentration to (blank) concentration. (Blank) energy is required.

diffuse

high

low

no

Water diffuses across a membrane by osmosis from the region of (blank) solute concentration to the region of (blank) solute concentration

low

high

(think of it as high water concentration to low water concentration, since water is the solvent)

Differentiate hypertonic, hypotonic, and isotonic

Hypertonic: Higher solute concentration relative to the inside of the cell

Hypotonic: Lower solute concentration relative to the inside of cell

Isotonic: Equal concentration of solutes inside and out

Animals that live in hyper or hypotonic environments need a mechanism to prevent excessive uptake or loss of water. This mechanism is called (blank), or the control of water balance.

Osmoregulation

Osmosis causes animal cells to (blank) in a hypertonic solution, and (blank) in a hypotonic solution.

Shrink (cells must expel water to equalize concentration)

Swell (cells must take in water to equalize concentration)

Plant cells are happiest in (blank) solutions because cell walls prevent the membrane from (blank) making them turgid.

Hypotonic (they can take in lots of water)

Rupturing

Only (blank) non-polar molecules can (blank) freely through the lipid bilayer

small, diffuse

(blank blanks) can move solutes across a membrane (blank) a concentration gradient.

Transport proteins

Against

Active transport requires energy in the form of (blank)

ATP

The movement of large molecules or particels to the outside of the cell is a type of active transport called (blank)

Exocytosis

Active transport of large molecules or particles to the inside of the cell is called (blank). This works when the membrane (blanks) upward, trapping material from the outside.

Endocytosis

Folds

Facilitated diffusion is a form of (blank) transport, where substances move (blank) a concentration gradient through transport proteins.

PASSIVE (this is the one kind of protein helped transport that is still passive!)

With, or down

All of the reactions in a cell constitutes the (blank blank)

There are two general types of reactions:

Cellular metabolism

Catabolic pathways, and Anabolic pathways

Catabolic pathways (blank) energy by (blanking) molecules into simpler compounds.

Release

Breaking down

Anabolic pathways (blank) energy to (blank) complex molecules from (blank) compounds.

Consume

build

simpler

Anabolic and Catabolic reactions are coupled together by (blank)

ATP

The energy released from (blank) reactions are used to drive (blank) reactions, also known as energy (blank). Most of this process is mediated by (blank)

exergonic

endogonic

coupeling

ATP

ATP consists of which 3 main parts?

Nitrogenous base adenine

5-carbon sugar called ribose

3 phosphate groups

ATP powers cellular work through (blank), which happens when ATP is hydrolyzed (split by gaining a water molecule) and transfers its phosphate group to the (blank)

phosphorylation

reactant

When exergonic reactions release energy, how is that energy stored?

Stored as ATP molecules

Enzymes are proteins that act as (blanks)

How many times can an enzyme be used?

Catalysts

Can be used several times

Enzymes speed up reactions by (blanking) the activation energy for the reaction

lowering

Enzymes are selective due to (blank) meaning only one kind of reaction can occur within them

shape

Differentiate substrate and active site

Substrate: the specific reactant to which the enzyme acts

Active site: The site on an enzyme where the substrate binds and reaction occurs

Enzyme inhibitors are chemicals/substances that (blank) with enzyme activity

List a type of enzyme inhibitor

interfere, disrupt

drugs, pesticides, poisons

What are the two types of enzyme inhibitors?

Competitive and noncompetitive

What do competitive enzyme inhibitors do?

physically block substrates from entering the active site, reducing productivity (competitive=aggressive)

What do noncompetitive inhibitors do?

bind somewhere other than the active site

they alter the shape of the active site and prevent the substrate from binding

(noncompetitive=nonviolent or non-invasive)

Feedback inhibition: a (blank) may act as an inhibitor of one of the enzymes that produced it

product