college biology chapter 6

What is the 1st law of thermodynamics?

Energy cannot be created or destroyed
Constant in the universe
Can increase in one area as it is decreasing in another
Can change forms
Cannot disappear

What is the 2nd law of thermodynamics?

When energy is transferred, it is converted into a less concentrated form

What is the most common form of low quality energy?

Heat

Do the molecules of life form spontaneously?

No

What do cofactors include?

Metal ions and coenzymes

What are cofactors useful for?

they shift electrons or easily give up or accept electrons in the metabolic process

What are endergonic reactions?

Require a net input of energy

What are examples of endergonic reactions?

Photosynthesis, anabolic, biosynthesis

What are exergonic reactions?

Use energy and release excess energy

What are examples of exergonic reactions?

Cellular (aerobic) respiration, catabolic, degradative

What is the formula for photosynthesis?

6 CO2 + 6 H2O →C6H12O6 + 6 O2
In the presence of light

What does photosynthesis represent?

Decrease in cellular entropy

Are photosynthesis reactants or products more stable?

Reactants

What is ATP?

an energy storage molecule that easily gives up a phosphate, is made by all cells, and primes stable molecules to react

What is ATP compared to?

Currency

Why do enzymes change shape?

to facilitate certain reactions

What do enzymes sometimes require?

cofactors

What must an enzyme have?

suitable substrate

What do enzymes do?

control the speed of a reaction and may place physical stress on the bonds of the substrate

What do antioxidants do?

Break down free radicals

What are free radicals?

Any substance that the cell makes that is toxic

When a ___ binds with a ___ it is not permanently or strongly bound.

enzyme; substrate

What do allosteric inhibitors do?

bind to an enzyme's allosteric site to keep substrates from binding to the enzyme or cause the substrate to release from the enzyme

What do allosteric activators do?

bind to an enzyme's allosteric site to cause the substrate to bind to the enzyme

What might effect enzyme activity?

Temperature, pH, salinity, the presence of certain chemicals, metabolic conditions, and feedback inhibiton

Coenzymes such as what diffuse freely through the cytoplasm?

NAD+ and NADP+

What happens in oxidation-reduction reactions?

one molecule gains an electron and one gives up an electron, and H+ are usually relased

___ sites have active sites where ___ molecules bind and other sites that bind with inhibitor or activator molecules

allostollic; substrate

Kilocalorie

unit of energy equal to 1,000 claories

Entropy

measure of disorder in a system // the measure of the amount of concentrated energy that has been dispersed in a system

Metabolism

the cells capacity to acquire energy and do work

First or second law of thermo?
Apple trees absorbing energy from the sun and storing the energy in the chemical bonds of starch and sugar

1st

First or second law of thermo?
A hydro electric plant at a waterfall, producing electricity

1st

First or second law of thermo?
A cup of hot cofee cooling over time

2nd

First or second law of thermo?
The glow of an incandescent bulb following the flow of electrons through a wire

1st

First or second law of thermo?
Earth's sun continuously losing energy to it surroundings

2nd

First or second law of thermo?
The movement of a gasoline-powered automobile

1st

First or second law of thermo?
Humans running the 100-meter dash following usual food intake

1st

First or second law of thermo?
The death and decay of an organism

2nd

The ___ law of thermo states that entropy is constantly increasing in the universe

Second

True or False?
When you eat a potato, some of the stored chemical energy of the food is converted into kinetic energy that moves your muscles

True

True or False?
The amount of low-quality energy in the universe is decreasing?

False, it is increasing

True of False?
No energy conversion can ever be 100 percent efficient

True

Activation energy

energy needed to start a chemical reaction

Phosphorylation

Removing phosphates

ATP/ADP cycle

breaking and reforming bonds in ATP

Substrates

chemicals that bond to enzymes

Active sites

positions on enzymes where substrates attach

Transition state

when substrate bonds reach their breaking point and the reaction will run spontaneously to product

Induced-fit model

substrate is not quite fitting the enzyme and the enzyme changed shape slightly

Enzymes act as biological ___ that speed up chemical reactions in cells

catalysts

___ can aid enzymes by accepting and donating

coenzymes

Endergonic or exergonic?
Burning wood at a campfire

Exergonic

Endergonic or exergonic?
The products of a chemical reaction have more energy than the reactions

Endergonic

Endergonic or exergonic?
Glucose + oxygen → carbon dioxide + water + energy
What is that formula?

Exergonic; Glucose

Endergonic or exergonic?
The reactants of chemical reaction have more energy than the product

Exergonic

The reaction releases energy

Exergonic

intermediates

compounds formed between the beginning and end of a metabolic pathway

energy carriers

Mainly ATP; donate energy to reactions

enzymes

proteins (usually) that catalyze reactions

degradative pathway

organic compounds are broken down to release energy (catabolic)

biosynthetic pathway

Complex organic compounds are built from simpler molecules (anabolic)

chemical equilibrium

the rate of the forward reaction is equal to the rate of the reverse reaction

metabolic pathway

an orderly series of reactions catalyzed by enzymes

cyclic pathway

a pathway in which the last step regenerates a reactant molecule used in the first step

entropy

a measure of the disorder of a system / measure of the amount of concentrated energy that has been dispersed in a system

Metabolism

includes all of the activities by which a cell acquires energy and materials and uses them to build, break apart, store, and release substances in controlled processes that are typical for that cell

kilocalorie

the measure of energy that can heat 1,000 grams of water from 14.5C to 15.5C at a standard pressure

chemical energy

the potential energy stored in the attractive forces (bonds) that cause atoms to group together into molecules

heat

also called thermal energy, resulting from collisions among molecules and their surroundings is a kind of kinetic energy

cofactors

small molecules and metal ions that assist enzymes or serve as carriers

transport proteins

membrane-bound substances that adjust concentration gradients in ways that influence the direction of metabolic reactions

reactants (substrates)

substances able to enter into a reaction