Enzymes L3

Enzymes L3

Multiple Choice

Organelles that make proteins by putting together chains of amino acids.

• Mitochondria

• Lysosomes

• Ribsomes

• Chloroplast

Multiple Choice

All amino acids have a ...

• ether group & carboxyl group

• amino group & hydroxide group

• amino group & carboxyl group

• ether group & hydroxide group

Multiple Choice

If a amino acid is Non-polar it is

• Hydrophobic

• Hydrophilic

Multiple Choice

Any substance that is acted upon by an enzyme is called a(n)?

• Coenzyme
• Substrate
• Vitamin
• Polypeptide

Multiple Choice

What is a substance called if it speeds up a chemical reaction?

• reusable
• catalyst
• specific
• fragile

Multiple Choice

What is a cofactor (L1)?

• A carbohydrate side chain that activates an enzyme.

• A non-protein that is bound to an enzyme and is required for catalysis.

• A requirement for the hydrolysis of urease.

• A non-protein that is not attached to the enzyme structure.

Multiple Select

Which are cofactors?

• A catalase molecule

• Coenzymes

• Polypeptides

• Prosthetic groups

Poll

Which environmental factors do you think might affect enzyme action?

• Temperature

• Moisture availabilty

• Substrate concentration

• pH

• Salinity

The optimum temperature range varies for different enzymes.

Multiple Select

What conditions do you think would be optimal for the action of pepsin?

• 37 - 42 degrees Celsius

• 32 - 36 degrees Celsius

• pH 1.5 - 2.0

• pH 4.5 - 7.0

Vm is the maximum level of enzyme activity and cannot be exceeded.

Multiple Choice

Vm is reached when...

• maximum temperature is reached.

• The pH is optimal.

• Roughly 50% of enzymes are bound to substrate.

• the enzyme is saturated.

Poll

Can you confidently explain what a cofactor is?

• Yes!

• Not sure

• No.

Enzyme Inhibitors

chemicals which bind to an enzyme to suppress its activity

Reversible inhibitors either bind to an active site (competitive inhibitors), or to another site on the enzyme (non-competitive inhibitors).

Multiple Choice

You are given a reaction and are told it is at “saturation.” To determine if this is true, you should add _______ and see if the reaction rate _______.

• ATP; increases

• more substrate; increases

• a competitive inhibitor; decreases

• a downstream product; decreases

• a noncompetitive inhibitor; decreases

Multiple Choice

Which explanation best fits the graph for pH's effect on an enzyme?

• As the pH gets closer to neutral more H-Bonds are broken
• Larger numbers of H+ & OH- ions distort the active site
• There are more collisions between substrates and active sites near the optimal pH
• Low pHs cause more H-Bonds to happen near the active site

Multiple Choice

Molecules that bind to enzymes and enhance an enzyme's ability are called:

• CoFactors
• CoEnzymes
• Allosteric Inhibitors
• Allosteric Activators

Multiple Choice

When a molecule can occupy the same active site as the substrate, a situation called __________________ can result

• Competitive lnhibition
• Allosteric Regulation
• Non-Competitive Inhibition
• Feedback Inhibition

Multiple Choice

The molecule an enzyme is working on is called the:

• Substrate
• Solvent
• Allosteric Inhibitor
• CoEnzyme

Multiple Choice

At low temperatures enzyme activity declines because of:

• Denaturation
• Decreased Kinetic Motion
• Increased H-Bonding
• Dissociation of Ionic Compounds

Multiple Choice

At high temperatures enzyme activity declines because of:

• Denaturation
• Decreased Kinetic Motion
• Increased H-Bonding
• Dissociation of Ionic Compounds

Multiple Choice

Enzymes catalyze reactions by ___________ Activation Energy.

• Increasing
• Decreasing

Multiple Choice

The current model of enzyme action is referred to as the:

• Induced Fit Model
• Lock & Key Model
• Singer-Nicolson Model
• Davson-Danielli Model