BIO 210- EXAM 2 Latest

BIO 210- EXAM 2 (Latest 2025/ 2026 Update) Grade A| 100% Correct (Verified Answers) QUESTION Define metabolism and describe the fundamental difference between anabolism and catabolism - ANSWER -Metabolism is involved with the buildup and breakdown of macromolecules within a cell; these chemical reactions provide energy and create substances that sustain life

-Catabolism: breaks down complex molecules; provides energy and building

blocks for anabolism; EXERgonic

-Anabolism: uses energy and building blocks to build complex molecules;

ENDERgonic QUESTION Identify the role of ATP as an intermediate between catabolism and anabolism - ANSWER 1. catabolism releases energy by oxidation of molecule

• energy is stored in molecules of ATP
• anabolism uses energy to synthesize macromolecules that make up the cell
• energy is released by hydrolysis of ATP

QUESTION Identify the components of an enzyme. What is a coenzyme? -

ANSWER -apoenzyme: protein portion

- cofactor: nonprotein part

- holoenzyme: apoenzyme plus cofactor

-coenzyme: organic cofactor

QUESTION Describe the mechanism of a enzymatic action - ANSWER A substrate binds to the active site on the protein to create a enzyme-substrate 1 / 3

complex. Then the substrate is created into a product and the process starts all over again."lock and key" QUESTION List the factors that influence enzymatic activity. What happens to an enzyme below its optimal temperature? Above its optimal temperature? -

ANSWER Factors:

• temperature
• pH (7 is neutral)
• substrate concentration
• inhibitors

Below = molecules move slowly and don't have enough energy to cause chemical reactions Above = denatures the proteins and reaction rate falls QUESTION Distinguish competitive and noncompetitive inhibition - ANSWER -competitive: fill the active site of an enzyme (compete with substrate for active site); can be reversible (can be overcome by increasing the concentration of the substrate) or irreversible.-noncompetitive: interact with another part of the enzyme (allosteric site) in a process called allosteric inhibition; causes the active site to change its shape making it non-functional; reversible IF the active site can return to its original shape QUESTION Explain the term oxidation-reduction. Why is glucose such an important molecule for organisms? - ANSWER -oxidation-reduction: oxidation is the removal of electrons from an atom/molecule (produces energy); reduction is adding electrons to an atom/substance. These reactions are ALWAYS paired; does NOT require oxygen.

• Glucose is a highly reduced compound containing a large amount of potential

energy because it has so many hydrogen atoms. 2 / 3

QUESTION Provide examples of two types of phosphorylation reactions that generate ATP - ANSWER 1. Substrate-level phosphorylation: ATP is generated when a high energy P is transferred from a phosphorylated compound to ADP

2. Oxidative phosphorylation: electrons are passed from organic compounds to

electron carriers and brought to ETC to generate ATP QUESTION Explain the overall function of metabolic pathways - ANSWER To break down larger components through a series of oxidation-reduction reactions to extract energy from organic compounds and store it in ATP Describe the chemical reactions of glycolysis - ANSWER Step 1: Glucose enter cell & is phosphorylated which requires a molecule of ATP creating G6P.

Step 2: G6P is rearranged to form Fructose 6P

Step 3: Another ATP molecule is used to form Fructose 1, 6-diphosphate

Step 4: An enzyme splits the sugar into two 3 Carbon molecules (DHAP & GP)

Step 5: DHAP readily converted to GP (reverse can occur too)

Step 6: The next enzyme oxidizes each GP (2 molecules since DHAP can be

converted to GP) by the transfer of 2 hydrogen atoms to NAD+ to form NADH (so

• NAD+ and 2 NADH) it also converts each GP to two 3-carbon compounds.

These two actions together create a high energy bond between the sugar and a phosphate of each new compound (P=CCC-P)

Step 7: The high energy P on each is moved to 2 ADP (1 each) forming 2 ATP

Step 8: An enzyme relocates the remaining P in each molecule

Step 9: A water molecule is removed from each (2 H20) forming 2 PEP molecules

each containing another high energy P bond

Step 10: The high energy P on each is moved to 2 ADP (1 each) forming 2 ATP

QUESTION Describe the chemiosmotic model for ATP generation. How do carrier molecule function in the electron transport chain? - ANSWER

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