Chapter 6 Sapling

How do organisms use energy, according to the first law of thermodynamics? -Animals eat to obtain chemical energy that they convert into kinetic energy -Photosynthetic organisms, such as plant, create their own energy by photosynthesis -The light energy collected during photosynthesis is converted to chemical energy -Plants destroy energy when they produce fruits, so the energy is no longer available in any form -Animals have more energy than plants because they generate more heat

-Animals eat to obtain chemical energy that they convert into kinetic energy -The light energy collected during photosynthesis is converted to chemical energy

How do enzymes lower the activation energy of a reaction? -by producing conditions within the active site conductive to the reaction -by using product molecules in the allosteric site to disable the active site -by stressing a bond in a substrate that needs to be broken -by forming a temporary bond between the active site and the substrate

-by producing conditions within the active site conductive to the reaction -by stressing a bond in a substrate that needs to be broken -by forming a temporary bond between the active site and the substrate

Select the statements that describe the energy cells use to drive cell processes. -The energy stored in chemical bonds is a form of potential energy -Plants use the energy in sunlight to power cell processes when ATP is not available -ATP is a form of chemical energy that is used to power cell processes -ATP is a form of long-term energy storage in plants

-the energy stored in chemical bonds is a form of potential energy -ATP is a form of chemical energy that is used to power cell processes

Identify whether the example describes an anabolic or catabolic pathway. -glycolysis converts one molecule of glucose to two molecules of pyruvate -a protein molecule is constructed from amino acid subunits -photosynthesis generates storage carbohydrates from CO2 and H2O -a nucleic acid molecule is broken down into nucleotide subunits

Anabolic: -Photosynthesis generates storage carbohydrates from CO2 and H2O -A protein molecule is constructed from amino acid subunits Catabolic: -Glycolysis converts one molecule of glucose to two molecules of pyruvate -A nucleic acid molecule is broken down into nucleotide subunits

The second law of thermodynamics states that the entropy, or disorder, in a system constantly increases. How do biological systems remain highly ordered?

Biological systems require an input of energy to remain highly ordered.

Classify the given scenarios as endergonic or exergonic. -generating carbohydrates in photosynthesis -pedaling a bike up a steep hill -a ball rolling down a hill -constructing DNA from nucleotides -metabolizing proteins into amino acids -breaking down glucose in cellular respiration

Endergonic: -generating carbohydrates in photosynthesis -pedaling a bike up a steep hill -constructing DNA from nucleotides Exergonic: -a ball rolling down a hill -breaking down glucose in cellular respirations -metabolizing proteins into amino acids

What does the first law of thermodynamics state about energy?

Energy can be transformed, but it cannot be either created or destroyed

A specialized protein in saliva breaks up starch molecules in food into smaller chains of simple sugars. In this reaction, which molecule is the enzyme, which is the substrate, and which is the product? One of the four answer choices will not be used. -the specialized protein -the small chains of simple sugars -the starch molecules -the saliva

Enzyme: the specialized protein Substrate: the starch molecules Product: the small chains of simple sugars

Both photosynthesis and cellular respiration are cellular processes that involve glucose. How do these two processes differently affect the metabolism of glucose?

Glucose is produced during photosynthesis to hold the energy gathered from light, whereas glucose is broken down during cellular respiration to release stored cellular energy.

Classify the examples of Kinetic energy or Potential energy -water falling down a waterfall -a compressed spring -wind blowing through a windmill -water held behind a dam -gasoline sitting in a gas can -released spring retracting a ballpoint of a pen

Kinetic energy: -water falling down a waterfall -a released spring to retracting a ballpoint on a pen -wind blowing through a windmill Potential energy: -gasoline sitting in a gas can -a compressed spring -water held behind a dam

Classify the following descriptions of enzyme inhibition as either reversible inhibition or irreversible inhibition. -forms a hydrogen bond with the enzyme -many are toxins that interfere with metabolic processes -forms a covalent bond with the enzyme -enzyme becomes active when the inhibitor is removed from the environment -enzyme remains inactive when the inhibitor is removed from the environment -prevents the cell from producing unneeded resources

Reversible: -forms a hydrogen bond with the enzyme -enzyme becomes active when the inhibitor is removed from the environment -prevents the cell from producing unneeded resources Irreversible: -forms a covalent bond with the enzyme -enzyme remains inactive when the inhibitor is removed from the environment -many are toxins that interfere with metabolic processes

How does the shape of a competitive enzyme inhibitor determine its mechanism of inhibition

The inhibitor has a similar shape to the substrate. The inhibitor is bound by the active site of the enzyme, preventing the substrate from being bound by the active site.

Why does the body use chemical energy?

The potential energy stored in chemical bonds can be released to perform work within a cell.

How do enzymes recognize their substrates?

a binding site that fits the shape and complements the charge of the substrate

Entropy is

a measure of the disorder or energy dispersal in a system

Which of these describes an anabolic pathway?

a pathway that generates molecules from smaller subunits

What describes how cofactors and coenzymes affect the function of enzymes?

increase catalytic function

Activation energy is best defined as the energy that

is required to bring the reactant molecules to a transition state

An enzyme catalyzes a reaction is a way that results in a lower activation energy. What is the significance of a lower activation energy?

it increases the rate of cellular reaction

What is energy?

the capacity of a system to do work

What is free energy (G)

the energy that may be used to perform work

What change occurs when an enzyme binds to a substrate with induced fit?

the shape of the enzyme's active site changes to better fit the substrate

You have been hired to develop a drug to inhibit the action of a certain enzyme. Where should the drug bind to allosterically inhibit the enzyme?

to a site on the enzyme other than the active site