AP Bio Cellular Energetics (Unit 3)

Glucose, starch, and fat are all …-…

energy rich

Energy is packed in … …. holding the molecules together

chemical bonds

Study of how cells release energy in bonds when needed, or store it away when not needed

Bioenergetics

Bioenergetics is the study of how energy from the sun is transformed into … … … …

energy in living things

During chemical reactions, chemical bonds are either … or ….

broken or formed

Process of forming or breaking down chemical bonds involves …, no matter which direction we go

energy

Every chemical reaction involves a … in ….

change in energy

First Law of Thermodynamics

Energy cannot be created or destroyed

Second Law of Thermodynamics

Energy Transfer leads to less organization

Entropy

disorder in organization

In order to power cellular processes, energy input must … … … to maintain order

exceed energy loss

Many … … …. to make energy transfer more ….

pathways are sequential, efficient

In sequential pathways, the product of one step is often the … for the next step in a process

reactant

A lack of … …. or order results in … for an organism

energy flow, death

Reactions when the products have less energy than the reactants

Exergonic Reactions

Exergonic reactions result in less energy in products because energy is … … during the reaction

given off

The course of a reaction can be represented by an …

energy diagram

Reactions that requires an … … …. are called endergonic reactions

input of energy

In endergonic reactions, the products have … …. than the reactants

more energy

Even though exergonic reactions … …, the reaction may not occur naturally without a little … to get things going

release energy, energy

In order for an exergonic reaction to start, the reactants must turn into a … … … called the **transition state** before turning into a product

high energy molecule

The transition state is sort of the …-….. … … that is difficult to achieve

reactants-products hybrid state

In order to reach transition state, a certain amount of energy is required - called … …

activation energy

Chemical bonds must be …. before … … can form

broke, new bonds

The energy barrier (hump in graph) is called…

Activation energy

Once a set of reactants has reached its activation energy, the rest of the reaction is all ….

downhill

Something that speeds something up

catalyst

Biological catalysts that speed up reactions

enzymes

Enzymes speed up reactions by lowering the … … and helping the … …. …

activation energy, transition state form

Enzymes let reactions occur …. because the transition state isn’t as hard to overcome

quickly

Enzymes ONLY lower the … …

activation energy

Most crucial reactions that occur in the cell requires …

enzymes

Enzymes are highly …

specific

Each enzyme catalyzes only … … of reaction

one kind

The concept of enzyme only catalyzing one kind of reaction is known as … …

enzyme specificity

Enzymes are usually named after the … … …

molecules they target

In enzymatic reactions, the targeted molecules are known as ….

substrates

Enzyme’s job in a reaction is to bring transition rate about by helping …. … …. ….

substrate get into position

Enzyme makes substrate get into position through a special region on enzyme called….

active site

Enzyme temporarily binds to one or more of the substrates to its active site and forms an …

enzyme-substrate complex

Structure of substrate – … and … – have to be compatible with the active site in order for the enzyme-catalyzed reaction to occur

shape and charge

Once reaction occurred and product is formed, the enzyme is released from the … and …. to its original state

complex, restored

By … and …. substrates over and over again, the enzyme the reaction along

binding and releasing

The enzyme speeds the reaction, allowing cells to release much needed energy from …. …

various molecules

Enzyme increases the rate of reaction by lowering the reaction’s … …

activation energy

Enzymes form temporary …-… ….

enzyme-substrate complexes

Enzymes remain ….. by the reaction

unaffected

Enzymes don’t …. the reaction

change

Enzymes have to change its …. to accommodate shape of substrates

shape

the action of enzymes changing its shape to accommodate the shape of substrates is called an … ….

induced fit

Because the fit needs to be perfect between the enzyme and the substrate, the enzymes only operate under … … of … ….

strict set of biological conditions

Enzymes need a little help in catalyzing a function – factors known as ….

cofactors

Cofactors can either be … or ….

organic or inorganic

Cofactors which are organic molecules are called …

coenzymes

Cofactors can also be ..

ions

Inorganic cofactors are usually …. ….

metal ions

Vitamins are examples of … ….

organic coenzyme

Examples of organic coenzymes are …

vitamins

Enzymatic reactions can be influenced based on factors such as … and ….

temperature and pH

The …. of enzyme and substrate will determine speed of reaction

concentration

The rate of reaction increases with … …., up to a point

increasing temperature

There is a point in which the rate of reaction increases with increasing temperature, because an increase in temperature of reaction increases … of ….

frequency of collisions

Too much heat can … an enzyme

damage

If reactions are conducted at an excessively high temperature, the enzyme loses its …-… … and becomes ….

three-dimensional shape, inactivated

Enzymes damaged by heat and deprived of their ability to catalyze reactions are said to be …, or disrupted

denatured

Enzyme denature is reversible if original … … …. of enzymes are restored

optimal environmental conditions

All enzymes operate at an … ….

ideal temperature

Not all organisms have a … body temperature

constant

Enzymes function best at a particular … level

pH

The relative …. of substrates and products also affect the rate of an enzyme-catalyzed reaction

concentration

The increase in substrate concentration will initially … … the reaction, but once all of the enzymes are bound by substrate, the reaction can no longer do so

speed up

Concentration of substrate where all enzyme in a reaction are bound by substrate

saturation point

Additional substrate passed the point of SATURATED POINT will make the enzyme no longer….

increase speed of reaction

Enzymes control the rate of … …

chemical reactions

A cell controls enzymatic activity by regulating the conditions that influence the … of the enzyme

shape

Other than the active sites, there are other sites known as … …

allosetric sites

If the substance has a shape that fits the active site of an enzyme, it can compete with the enzyme and block the substrate from getting in the … …

active site

Substance with same shape of enayme competing with substrate and blocking the enzyme from getting in the active site is known as … ….

competitive inhibition

If there was … … available, the substrate would …-…. the inhibitor and the reaction WOULD occur

enough substrate, out-compete

If an inhibitor binds to an allosteric site, it is a ….

allosteric inhibitor

Allosteric inhibitors are ….. ……

noncompetitive inhibitions

A noncompetitive inhibitor generally … the … … so it cannot function

distorts, enzyme shape

In allosteric inhibitors, the substrate can still bind to the …. …, but the enzyme CAN’T ….. the reaction

active site, catalyze

Cells acquire energy it needs without becoming a MAJOR MESS with …. ….

ATP

ATP consists of a molecule of …. bonded to … …

adenosine, three phosphates

When a cell needs energy, it takes ATP and … … the … …, making **aDP and one loose phosphate**

splits off the third phosphate

The energy released from ATP -→ ADP and P and energy can be put to … …

whatever use

ATP is … and … … …

neat and easy to form

Organisms use …. … that increase energy (like breaking down ATP) to power … … (like building macromolecules)

exergonic, endergonic reactions

Majority of ATP is formed through … …

Cellular respiration

Cellular respiration is the process of … … .. and making ….

breaking down sugar, ATP

In autotrophs (Plants, the sugar is formed through ….

photosynthesis

In heterotrophs, glucose is from … … …

food we eat

…, …, …. are producers

plants, algae, cyanobacteria

The earliest photosynthesis was done by … …, and later …. developed photosynthetic abilities

prokaryotic cyanobacteria , eukaryotes

Photosynthesis is the conversion of …. energy to … energy

light, chemical

….. … and … are raw materials used to manufacture

carbon dioxide and water

There is strong evidence that prokaryotic photosynthesis contributed to …. .. … in the atmosphere

production of oxygen

Prokaryotic photosynthesis pathways laid the … … for eukaryotic photosynthesis to develop

evolutionary foundation

There are two stages in photosynthesis : .. … (also called light-dependent reactions), and the … … (also called light-independent reactions)

light reactions, dark reactions