Unit 2 Slides Flashcards by Kaitlyn Jasper

Metabolism

is the totality of an organism’s chemical reactions

emergent property of life that arises from interactions between molecules within the cell

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metabolic pathway

begins with a specific molecule and ends with a product

Each step is catalyzed by a specific enzyme

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Catabolic pathways

release energy by breaking down complex molecules into simpler compounds

Cellular respiration, the breakdown of glucose in the presence of oxygen, is an example of a pathway of catabolism

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Anabolic pathways

consume energy to build complex molecules from simpler ones

The synthesis of protein from amino acids is an example of anabolism

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Bioenergetics

is the study of how organisms manage their energy resources

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Energy

Is the capacity to cause change

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4 forms of energy

Kinetic
Heat
Potential
Chemical

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Kinetic energy

Is energy associated with motion

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Thermal/Heat energy

Is kinetic energy associated with random movement of atoms or molecules

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Potential energy

Is energy that matter possesses because of its location or structure

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Chemical energy

Is potential energy available for release in a chemical reaction

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Thermodynamics

The study of energy transformations

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Isolated system

Is isolated from its surroundings

liquid in a thermos

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Open system

Energy and matter can be transferred between the system and its surroundings

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Organisms are…

Open systems

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First law of thermodynamics

The energy of the universe is constant

Energy can be transferred and transformed but it cannot be created or destroyed

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Second law of thermodynamics

During every energy transformation, some energy is unusable, and is often lost as heat

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Every energy transfer or transformation increases the ___ of the universe

Entropy

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Spontaneous processes

Occur without energy input; they can happen quickly or slowly

Rust

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For a process to occur without energy input, it…

Must increase the entropy of the universe

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Cells create ___ structures from ___ ___ materials

Ordered
Less ordered

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Organisms also replace ___ forms of matter and energy with ___ ___ forms

Ordered
Less ordered

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Energy flows into an ecosystem in the form of ___ and exits in the form of ___

Light
Heat

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Entropy (disorder) may decrease in an organism, but…

The universes total entropy increases

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Free energy

Is energy that can do work when temp and pressure are uniform (as in a living cell)

Free-energy change formula

∆G = ∆H – T∆S

Entropy is

Disorder

Every transfer or transformation leads to

Entropy

If the ∆G is - it is

Spontaneous

∆G ∆H – T∆S

Free energy (G) Total energy (H) Entropy (S) and kelvin (T)

Free energy is a measure of a systems

Instability It’s tendency to change to a more stable state

During a spontaneous change

Free energy decreases and the stability of a system with increase

Equilibrium is

A state if maximum stability

More entropy =

More random or farther apart = spontaneous

Exergonic reaction

Proceeds with a net release of free energy and is spontaneous

Endergonic reaction

Absorbs free energy from its surroundings and is non spontaneous

Reactions in a ___ system eventually reach ___ and then do ___ work

Closed Equilibrium No

Cells are not in equilibrium; they are ___ systems experiencing a ___ flow of materials

Open Constant

Metabolism is

Never at equilibrium

A catabolic pathway in a cell

Releases free energy in a series of reactions

Closed and open hydroelectric systems can serve as

Analogies Pull electrons = prions

A cell does 3 main kinds of work

Chemical Transport Mechanical

Energy coupling

The use of an exergonic process to drive an endergonic one

Most energy coupling in cells is mediated by

ATP

Is the cells energy shuttle

ATP is composed of

Ribose (sugar), adenine (nitrogenous base), and three phosphate groups

The bonds between the phosphate groups of ATPs tail can be broken by

Hydrolysis

The three types of cellular work ___, ___, and ___, are powered by the ___ of ATP

Mechanical, transport, and chemical Hydrolysis

The energy from exergonic reaction of ATP hydrolysis can be used to drive an ___

Endergonic reaction

Coupled reactions are (steal energy to another)

Exergonic

ATP is a

Renewable resource that is regenerated by addition of a phosphate group to ADP

Energy to phosphorylate APD comes from

Catabolic reactions in the cell

ATP cycle is a revolving door through which nerdy passes during its ___ from ___ to ___ pathways

Transfer Catabolic Anabolic

Catalyst

A chemical argent that speeds up a reaction without being consumed by the reaction

Enzyme

Is a catalytic protein

Hydrolysis of surprise by the enzyme sucrose is an ex of an

Enzyme-catalyzed reaction

Every chemical reaction between molecules involves

Bond breaking and bond forming

Activation energy

The initial energy needed to start a chemical reaction (Energy required in order to go)

Activation energy is often supplies in the form of

Thermal energy The reactant molecules absorb from their surroundings

Enzymes catalyze reactions by

Lowering the Ea barrier

Enzymes do not affect the change in free energy, instead

They hasten reactions that would occur eventually

For a bigger reaction you need

More enzymes

The reactant that an enzyme acts on is called the enzymes

Substrate

Enzymes binds to its ___, forming an ___

Substrate Enzyme-substrate complex

Active site

Is the region on the enzyme where the substrate binds

Induced fit

A substrate brings chemical groups of the active site into positions that enhance their ability to catalyze the reaction

The active site can lower an Ea barrier by

Orienting substrate correctl Straining substrate bonds Providing a favorable micro environment Covalently bonding to the substrate

An enzymes activity can be affect by

Bernal environmental factors (poor temp and pH) Chemical that specifically influence the enzyme

Optimal conditions favor the most ___ ___ for the enzyme molecule

Active shape

Cofactors

Are non proteins enzyme helpers

Cofactors may be ___ or ___

Inorganic or organic

Coenzyme

An organic cofactor

Coenzymes include

Vitamins

Competitive inhibitors

Bind to the active site of an enzyme, competing with the substrate (block the active spot)

Non competitive inhibitors

Bind to another part of an enzyme, causing the enzyme to change and making the active site less effective

Example of inhibitors include

Toxins, posing, pesticides, and antibiotics

Enzyme are proteins

Encoded by genes

Changes in genes

Lead to changes in amino acid composition of an enzyme

Altered amino acids in enzymes

May alter their substrate specificity

Allosteric regulations

May either inhibit or stimulate an enzymes activity

Allosteric regulation occurs

When a regulatory molecule binds to a protein at one site and affects the proteins function at another site

Most allosterically regulated enzymes are made from

Polypeptide subunits

The binding of an activator stabilizes the ___ form of the enzyme

Active

The binding of an ___ stabilized the inactive form

Inhibitor

Cooperativity

A form of allosteric regulation that can amplify enzyme activity

Caspases

Inhibition of proteolytic enzymes, may help management of inappropriate inflammatory responses

Feedback inhibition

The end product o fa metabolic pathway shuts down the pathway

Feedback inhibition prevents a cell from

Wasting chemical resources b synthesizing more product than is needed

Fermentation

Is a partial degradation of sugars that occurs without O2

Aerobic respiration

Consumer organic molecules and O2 and yields ATP

Cellular respiration

Included both aerobic and anaerobic respiration but is often used to refer to aerobic respiration

The transfer of electrons during chemical reactions releases energy is stored in

Organic molecules

Redox reactions

Chemical reactions that transfer electrons between reactants are called oxidation reduction reactions

Oxidation

A substance gains electrons, or is reduced (Amount of positive electrons is reduced)

Reducing agent

The electron donor

Oxidizing argent

The electron receptor

Some redox reactions do not transfer electrons but change

The electron sharing in covalent bonds

In cellular respiration

Glucose and other organic molecule are broken down in a series of steps

NAD+ is

A coenzyme

NAD+ functions as an

Oxidizing agent during cellular respiration

Electron transport chain

NADH passes the electrons to the

Glycolysis

Breaks down glucose into 2 molecules of pyruvate

Citric acid cycle

Completes the breakdown of glucose

Oxidative phosphorylation

Accounts for most of the ATP synthesis