The Working Cell (energy)

Question 1

Energy

Answer 1

Capacity to cause change.

Question 2

Kinetic energy

Answer 2

Energy an object has when it is in motion

Question 3

Potential energy

Answer 3

Potential energy is the stored energy in any object or system by virtue of its position or arrangement of parts.

Question 4

Heat

Answer 4

A type of kinetic energy in its most disordered, chaotic form, the energy of aimless molecular movement.

Question 5

Entropy

Answer 5

Measure of the amount of disorder, or randomness within a system.

Question 6

Chemical energy

Answer 6

Form of potential energy which arises from the arrangement of atom and can be released by a chemical reaction.

Question 7

Calorie

Answer 7

Is the amount of energy that can raise the temperature of 1 gram of water by 1´C.

Question 8

Kilocalorie

Answer 8

Units of 1000 caalories to describe the fuel content in food.

Question 9

Adenosine triphosphate (ATP)

Answer 9

“Energy currency” of the cell. It consists of an adenosine molecule bonded to three negative phosphate groups that repel each other.
ATP plays a crucial role in cellular processes by storing and transferring energy within cells. When ATP is broken down through hydrolysis, releasing one of its phosphate groups, it releases energy that can be used to power various cellular activities such as muscle contraction, protein synthesis, and active transport across cell membranes.
ATP can be restored by adding a phosphate group back to ADP.

Question 10

Metabolism

Answer 10

The total of all chemical reactions in an organism

Question 11

Enzymes

Answer 11

Molecules that speed up chemical reactions without being consumed by those reactions. They are mostly proteins but can occur as a RNA molecule.

Question 12

Activation energy

Answer 12

The energy that must be invested to start a reaction is called activation energy because it activates the reactants and triggers the chemical reaction.
It represents the energy required to break the bonds of reactant molecules and initiate the reaction.
Enzymes enable metabolism to occur by reducing the amount of activation energy required to break the bonds of reactant molecules.

Question 13

Substrate

Answer 13

The specific molecule that an enzyme acts on.

Question 14

Active site

Answer 14

A region of the enzyme that has a shape and chemistry that fit the substrate molecule.
When a substrate (lactose) lands on the active site (lactase) the site changes its shape slightly to embrace the lactose and catalyzes the reaction.

Question 15

Induced fit

Answer 15

Induced fit is when an enzyme changes its shape slightly to better accommodate and interact with its substrate during a chemical reaction.

Question 16

Enzyme inhibitors

Answer 16

Enzyme inhibitors are molecules that bind to enzymes and decrease their activity. They can do so by blocking the active site of the enzyme, preventing the substrate from binding, or by altering the enzyme’s shape or structure, making it less effective in catalyzing the reaction.

Question 17

Diffusion

Answer 17

Diffusion, as a form of passive transport, is the spontaneous movement of particles from an area of higher concentration to an area of lower concentration, driven by the random motion of particles. This process does not require the input of energy and leads to the equal distribution of particles within a given space, resulting in a uniform concentration gradient.

Question 18

Facilitated diffusion

Answer 18

Facilitated diffusion is a type of passive transport in biological systems where molecules move across cell membranes with the assistance of transport proteins. Unlike simple diffusion, facilitated diffusion involves the use of specific carrier proteins or channel proteins embedded in the cell membrane to facilitate the movement of certain molecules that cannot easily pass through the lipid bilayer.

Question 19

Osmosis

Answer 19

Osmosis is the passive movement of solvent molecules, usually water, across a semipermeable membrane from an area of lower solute concentration to an area of higher solute concentration. This movement occurs to equalize the concentration of solute on both sides of the membrane, resulting in the net movement of water molecules until equilibrium is reached.

Question 20

Hypertonic

Answer 20

Hypertonic describes a solution that has a higher concentration of dissolved particles (such as salts or sugars) compared to another solution. When a cell is in a hypertonic solution, the solution outside the cell has a higher concentration of dissolved particles than inside the cell. This can cause water to diffuse out of the cell through osmosis, resulting in the cell shrinking or shriveling, a process known as plasmolysis.

Question 21

Hypotonic

Answer 21

Hypotonic describes a solution that has a lower concentration of dissolved particles (such as salts or sugars) compared to another solution. When a cell is in a hypotonic solution, the solution outside the cell has a lower concentration of dissolved particles than inside the cell. This can cause water to diffuse into the cell through osmosis, potentially leading to the cell swelling or even bursting if too much water enters, a phenomenon known as cytolysis.

Question 22

Isotonic

Answer 22

Isotonic describes a solution that has the same concentration of dissolved particles (such as salts or sugars) as another solution. When a cell is in an isotonic solution, the concentration of dissolved particles inside and outside the cell is equal. In an isotonic solution, there is no net movement of water across the cell membrane, so the cell maintains its normal shape and volume.

Question 23

Osmoregulation

Answer 23

The control of water balance. Biological process by which organisms control the concentration of solutes and water within their bodies to maintain internal osmotic balance and proper physiological function. This process involves regulating the uptake, retention, and excretion of water and solutes

Question 24

Active transport

Answer 24

Cellular process that requires the expenditure of energy, usually in the form of adenosine triphosphate (ATP), to move molecules or ions against their concentration gradient, from an area of lower concentration to an area of higher concentration. This process involves specialized transport proteins, such as pumps or carriers, embedded in the cell membrane, which actively transport specific substances across the membrane.

Question 25

Exocytosis

Answer 25

Exocytosis is a cellular process by which cells actively release molecules, such as proteins, hormones, or neurotransmitters, from the interior of the cell to the extracellular environment. It involves the fusion of membrane-bound vesicles, containing the molecules to be released, with the plasma membrane, resulting in the discharge of the vesicle contents into the extracellular space.

Question 26

Endocytosis

Answer 26

Endocytosis is a cellular process by which cells internalize molecules, particles, or even other cells by engulfing them with their cell membrane. During endocytosis, a portion of the cell membrane invaginates or forms a pocket around the material to be internalized, eventually pinching off to form an intracellular vesicle. There are several types of endocytosis, including phagocytosis (engulfment of solid particles).