UNLV BIO 189: Exam 2

Chapter 4: Energy in cells (Basic), Enzymes, and Membrane transport | Chapter 6: | Chapter 23: | Chapter 27:

What is potential energy?

Stored energy thats available to do work

What is kinetic energy?

Energy of motion

What is 1 Cal (calorie) equivalent to?

Amount of energy to raise a gram of water’s temp by 1 Celsius

How much is a kcal (kilocalorie)?

1000 Cal

What is the first law of energy conservation?

Energy cannot be created or destroyed, but it can be converted to other forms

Energy cannot be created or destroyed…

But it can be converted to other forms.

Can the total amount of energy in the universe be changed?

No

Example of energy transformation

Photosynthesis, Cellular respiration, and etc.

What’s the second law of energy conservation?

All energy transformations are inefficient, every reaction loses energy to it’s surroundings through heat

What form produced by a reaction in which they lose ____ in surroundings?

Heat

What is Entropy?

Measure of randomness

The most disordered a system is…

The higher the entropy

The less disordered a system is…

The lower the entropy

Name something with high entropy

Water vapor (gas)

Name something with low entropy

Ice (solid water)

Organisms can inc in complexity as long as…

...something else dec in complexity by a greater amount

Organisms can dec in complexity as long as…

...something else inc in complexity by a greater amount

___ encompasses all of these chemical reactions in cells

Metabolism

Metabolic reactions are another term for

Chemical reactions in the cells, Refered to as metabolism

If a reaction requires an input of energy...

Products contain more energy than reactants

If a reaction releases energy…

Products contain less energy than reactants

Electrons can carry...

Energy

Most energy transformations in organisms occur in…

Redox (Oxidation-Reduction) reactions

What happens Redox (Oxidation-Reduction) reactions?

Transfer energized electrons from one reactant to another

What does Oxidation mean (in context to this exam)?

Loss of electrons and a corresponding loss of energy

What does Reduction mean (in context to this exam)?

Gain of electrons and a corresponding gain of energy

In Redox reactions, it’s like giving poop as a gift to a friend as a result their ____, or in this reaction, ____

Mood dec, Electron accepter dec

Oxidation and Reduction occur ________ because electrons removed from one molecule during oxidation must join another molecule and ____ it

Simultaneously, Reduce

In a electron transport chain, each protein...

...accepts an electron from the molecule before it passes it to the next

What happens to the proteins of the electron transport chain when accepting an electron and passing it on?

Each protein is first reduced and the oxidized

ATP is a type of ______

Nucleotide

What are the components of the nucleotide: ATP?

Adenine, Ribose, and the three phosphate groups

What are the three phosphate groups of ATP?

PO₄

What is the charge in the three phosphate groups in ATP?

Negative

The negative charges on the three phosphate groups repel each other, making the molecule unstable so...

It releases energy when a covalent bond between the two phosphate breaks

When a cell using ATP for energy, it is trying to...

Removing the endmost phosphate groups

What reaction to the cells use to break the endmost phosphate groups in ATP?

Hydrolysis

What are the products of a Hydrolysis reaction of harvesting energy from ATP?

Adenosine Diphosphate: the liberated phosphate group and Energy

What are coupled reactions?

Simultaneous reactions: where one provides energy and one drives the other

How do coupling reactions work?

Ex. Cell uses ATP by transferring it’s phosphate group to another molecule

What is an enzyme?

An organic molecule that speeds up chemical reactions without being consumed

How do enzymes speed up reactions?

Lowering activation energy

What is activation energy?

Energy needed to start a reaction

How does enzyme do enzyme things?

It binds to the shape of active site of substrates (reactants)

What is negative feedback ( also called feedback initiation)?

A change reverses the action that; that change made

What are the two ways that negative feedback uses to prevent too much substrate from forming?

Noncompetitive inhibition, Competitive inhibition

What is noncompetitive inhibition?

Inhibitor (Product molecules) bond to active site side , active site shape changes, enzyme cannot bond

What is competitive inhibition?

Inhibitor (Product molecules) bond to active site, blocks enzyme from bonding

How can an enzyme be denatured?

If pH or Salt concentration is too high/low, or if Temp is too high (37 Cel+ in humans)

Selective Permeability

Only certain things can pass through the membrane

How can stuff not allowed to pass through the cellular membrane go through?

Transport Proteins

What is a concentration gradient?

Solute is more concentrated in one region than neighboring region

What is Passive Transport?

Net Movement is down concentration gradient, does not require energy input

What is Simple diffusion

Substance moves across membrane without assistance from transport proteins

What is Osmosis?

Water diffuses across a selectively permeable membrance

What is Facilitated diffusion?

Substance moves across membrane with assistance from transport proteins

What is Active transport?

Net movement is against concentration gradient, requires transport protein and energy input (usually from ATP)

Two types of transport using vesicles?

Endocytosis,Exocytosis

What is Endocytosis?

Membrane engulfs incoming substance, enclosing it in vesicle

What is Exocytosis?

Vesicle fuses with cell membrane, releasing substances from the cell

What is Isotonic?

Condition when solute concentration is same on both sides of a selectively permeable membrane

What is Hypotonic?

Solute concentration is lower than it is inside the cell

What is Hypertonic?

Solute concentration is higher than it is inside the cell

What is Turgor pressure?

Force of water against cell wall (plants only)

What is the sodium-potassium pump in the cell membrane?

Protein that using energy (from ATP), Pumps Na+ out, Pumps K+ in

What is Pinocytosis?

Form of endocytosis when cell engulfs a large particle

What is Phagocytosis?

Form of exocytosis where small amount of substance/fluids are brough into cell by vesicles