Biology CH 4-6

This is where I will contain keywords and review questions for Biology Chapters 4-6

Hypertonic

Has more dissolved solutes

Hypotonic

contains less dissolved solutes

Negative Feedback

product of reaction slows production of more products

Kinetic Energy

energy of motion

Potential Energy

stored energy

What is the first law of thermodynamics?

1.Energy can change forms

2.Energy cannot be created nor destroyed.

What is the second law of thermodynamics?

the entropy of the universe is increasing.

Catabolic

Breaking down larger molecules

Anabolic

Building up larger molecules

What is ATP hydrolysis?

release of usable energy by splitting ATP into ADP + inorganic phosphate

What is ATP regeneration?

requires energy; combines ADP + inorganic phosphate to get ATP

Endergonic reaction

requires energy; higher energy in product

Exergonic reaction

releases energy; lower energy in product

competitive inhibition

binds to enzyme at active site; increasing substrate concentration may allow more substrate to outcompete inhibitor

non-competitive inhibition

binds to enzyme outside its active site; changes shape; excess substrate cannot restore activity

What is delta G?

How do enzymes affect activation energy and reaction rate?

It lowers required activation energy and speeds up reaction rate.

What are cofactors?

non-protein helpers required by some enzymes

What are conenzymes?

organic cofactors; many vitamins are coenzymes

Osmosis

The diffusion of water from a high to low concentration

Simple diffusion

molecules move from high to low concentration; no ATP required

Facilitated diffusion

molecules move down the gradient using passageways; no ATP required

What are channels?

hydrophilic passageways

What are carrier proteins?

bind substances and change shape

Passive transport

molecules move directly through bilayer; small non-polar molecules

Coupled transport

uses energy stored from an existing gradient; moves two things at once

What are symporters?

move two substances in the same direction

What are antiporters?

move two substances in opposite directions

What is chemiosmosis?

hydrogen ions flowing down their gradient through ATP synthase to make ATP

Endocytosis

vesicle bringing materials into the cell

Exocytosis

releasing materials outside the cell using vesicles

Phagocytosis

process cells use to move large particles in through the cell membrane (like pathogens)

Pinocytosis

extracellular fluid and dissolved substances

Receptor-mediated endocytosis

bringing in particular substances that bind to specific receptors.

What is turgor pressure?

Plants cells maintaining higher internal solute concentrations so water swells in the cells.

Where is potential energy stored?

In chemical bonds (usually carbon)

What is entropy?

randomness / disorder of the universe

What is an example of entropy?

heat

Oxidation

loss of electrons

Reduction

gain of electrons

Adenosine triphosphate

ATP; a nucleotide that temporarily captures and transfers usable energy within a cell.

Coupling

linking of energy-releasing reactions with energy-requiring reactions

Active transport

requires ATP

The sodium-potassium pump is an example of:

Primary-active transport

An allosteric activator binds to allosteric sites to keep an enzyme in its active configuration, thereby increasing enzyme activity. T/F?

True

In order to reuse an enzyme after the conclusion of an enzyme catalyzed reaction, what must occur?

the enzyme has to separate itself from the product

The accumulation of amino acids and sugars in animal cells can occur through what?

coupled transport

The synthesis of sugar molecules through the process of photosynthesis requires energy absorbed from sunlight. Bearing this in mind, what kind of reaction is photosynthesis?

endergonic

Osmosis occurs as water can cross the lipid bilayer through specialized channels or water movement called what?

aquaporins

Membrane fluidity is affected by what?

temperature, cholesterol, types of fatty acids.

Once ATP donates its phosphate to a coupled reaction it becomes ADP, The ADP…

can be recharged in an endergonic reaction to form ATP.

Do exergonic reactions require activation energy to get started?

Yes

Catalysts

Substances that influence chemical bonds in a way that decreases the activation energy.

The part of a membrane protein that extends through the phospholipid bilayer is primarily composed of amino acids that are..?

non-polar

Rate of enzyme-catalyzed reaction depends on what?

concentrations of substrate and enzyme

In biology, feedback inhibition is defined as what?

the mechanism by which the reaction's end product inhibits or controls the enzyme's function that helped make it.

A particular reaction has a negative delta G. However, this reaction takes many years to proceed in the absence of enzyme. Why is this the case?  

A certain amount of activation energy is required for the reaction to proceed

Which type of proteins is embedded in the cell membrane in both active transport and facilitated transport?

carrier

A molecule that closely resembles the shape of a substrate for an enzyme and that decreases the activity of the enzyme would most likely serve as

a competitive inhibitor.

In a hypotonic solution, animal cells:

swell and may burst