Chapter 6 and Chapter 8

Role of Enzymes in Catalyzing Biochemical Reactions

enzymes stabilize the transition state and decrease its free energy.

How do living organisms create macromolecules, organelles, cells, tissues, and complex higher-order structures?

living organisms create order locally, but the energy transformations generate waste heat that increases the entropy of the universe

non-spontaneous

means that a reaction requires a sustained input of energy.

ATP is a type of _____ and is composed of adenine, _____, and three phosphate groups.

nucleotide; ribose

Gibbs free energy

the amount of energy available to do work.

Entropy

the degree of disorder; individual nucleotides the total amount of energy multiplied by the absolute temperature (T, measured in degrees Kelvin

exergonic reaction

the energy released is more than the initial input of energy, so there is a net release of energy. ( release free energy )

photoheterotrophs

Some microorganisms gain energy from sunlight but obtain their carbon by ingesting organic molecules.

autotrophs

Some organisms are able to convert carbon dioxide (an inorganic form of carbon) into glucose (an organic form of carbon)

Carbon-carbon covalent bonds

Such as the ones in carbohydrates and lipids, weak and have a lot of potential energy.

ATP

(adenosine triphosphate) main energy source that cells use for most of their work. Extra: * Ribose is part of it

Macromolecules

1. Carbohydrates 2. Proteins 3. Fats 4. Nucleic acids

Subunits

1. Sugar 2. Amino acids 3. Fatty acids 4. Nucleotides

As a cat pounces on a mouse, its muscles consume 10 units of potential energy (which the cat previously gained from the food it consumed). However, the pounce itself only required 4 units of kinetic energy. How many units of energy were dissipated as heat?

6

transition state

As a chemical reaction proceeds, existing chemical bonds break and new bonds form. For an extremely brief period of time, a compound is formed in which the old bonds are breaking and the new ones are forming. This is the intermediate between reactants and products.

metabolism

Encompasses the entire set of chemical reactions that convert molecules into other molecules and transfer energy in living organisms. Is the set of chemical reactions that sustain life. Metabolism is divided into two branches: catabolism is the set of chemical reactions that break down molecules into smaller units and, in the process, produce ATP. Anabolism is the set of chemical reactions that build molecules from smaller units and require an input of energy, usually in the form of ATP.

allosteric enzymes

Enzymes that are regulated by molecules that bind at sites other than their active sites

Substrate

In a chemical reaction catalyzed by an enzyme, the reactant is often referred to. substrate (S) is converted to a product (P): S⇋P

inhibitors

Irreversible usually form covalent bonds with enzymes and irreversibly inactivate them. Reversible form weak bonds with enzymes and therefore easily dissociate from them.

How does the flow of energy through life differ from the flow of matter through life?

Matter can be recycled, while some energy is always converted to unusable forms like heat.

phototrophs

Organisms that capture energy from sunlight

chemoautotrophs

Other microorganisms extract energy from inorganic molecules but build their own organic molecules; these organisms.

chemotrophs

Other organisms derive their energy directly from chemical compounds.

heterotrophs

Other organisms do not have the ability to convert carbon dioxide into organic forms of carbon. Instead, they obtain their carbon from organic molecules synthesized by other organisms. These organisms eat other organisms or molecules derived from other organisms.

activation energy

The energy input necessary to reach the transition state.

The form of energy that is typically LEAST useful to life is energy in

The form of heat

Fermentation

a process for extracting energy from fuel molecules that does not rely on oxygen or an electron transport chain, but instead uses an organic molecule as an electron acceptor.

Thermal energy

a type of kinetic energy corresponding to the random motion of molecules and results in a given temperature.

ADP

adenosine diphosphate

AMP

adenosine monophosphate

chemical reaction

atoms keep their identity, but the atoms that share bonds change.

You have entered a 5K race. As you finish the last 500 meters, your body has converted _____ energy to _____ energy, and has lost some of this energy as _____.

chemical potential; kinetic; heat

Imagine that you discover a microbial deep-sea organism that can derive energy from (inorganic) hydrogen gas (H2). In addition, this microbe can synthesize organic compounds from carbon-containing inorganic molecules in the ocean. This microbe is a: Please choose the correct answer from the following choices, and then select the submit answer button. Answer choices

chemoautotroph

Imagine that you discover a carnivorous deep-sea fish that cannot utilize the carbon in carbonic acid, or any other inorganic molecule, present in seawater to form glucose, or other organic molecules. Living so far beneath the water's surface, this fish is also incapable of harnessing energy from the sun. This fish would be considered a:

chemoheterotroph.

Inhibitors

decrease the activity of enzymes.

The bond between the last two phosphate groups in ATP is relatively _____ to break because of the _____ between _____.

easy; repulsion; negative charges

The total amount of energy (H)

energy available to do work (G)+energy lost to entropy (TS)

first law of thermodynamics

energy can be transferred and transformed, but it cannot be created or destroyed.

Kinetic Energy

energy of motion

Which molecule has the greatest chemical potential energy?

glucose

Spontaneous

in this context means that a reaction releases energy

activators

increase the activity of enzymes.

Catabolism

is a set of chemical reactions that break down macromolecules into smaller units releasing energy ( ATP ) For example, carbohydrates can be broken down or catabolized, into sugars, fats into fatty acids and glycerol, and proteins into amino acids.

Organic molecules store _____energy in their _____ bonds.

potential; covalent

endergonic reaction

reactions with a positive ΔG that require an input of energy and are not spontaneous ( require free energy )

Which of the following is a part of ATP?

ribose

a friend tells you that his hamster has reached equilibrium. you

send a sympathy card since the hamster is dead

potential energy

stored energy

Anabolism

the set of chemical reactions that build macromolecules from smaller units and require and require an input of energy. ( Usually in the form of ATP ) Example: combining glucose molecules to form glycogen.

Enthalpy

the total amount of energy

Nearly all cells use ATP as their primary energy source. This is evidence that:

the use of ATP by cells evolved early in the history of life and has been conserved over time.

Carbon-carbon covalent bonds, such as the ones in carbohydrates and lipids, are _____ and have _____.

weak; a lot of potential energy

second law of thermodynamics

which states that the transformation of energy is associated with an increase in disorder of the universe. For example, when kinetic energy is changed into potential energy, the amount of disorder always increases.