Pathways in cells
What do anabolic pathways do in cells?
They build complex molecules from simpler ones, consuming energy
Distinguish between kinetic and potential energy
Kinetic energy is the energy of motion, while potential energy is stored energy based on an object's position or structure.
What is the first law of thermodynamics?
Energy cannot be created or destroyed, only transformed
Define "reactant"
A substance that takes part in and undergoes change during a reaction.
What is ATP?
Adenosine triphosphate, the primary energy carrier in cells
What do catabolic pathways do in cells?
They break down complex molecules into simpler ones, releasing energy.
What is chemical energy
Chemical energy is the potential energy stored in chemical bonds.
What is the second law of thermodynamics?
Every energy transfer increases the entropy (disorder) of the universe.
Define "product."
A substance that is formed as the result of a chemical reaction
Where is the bond that breaks to release energy in ATP? -
Between the second and third phosphate groups
What is metabolism?
Metabolism is the sum of all chemical reactions that occur within a cell to convert fuel into energy and build complex molecules.
Why is an organism considered an open system?
Because it exchanges energy and matter with its surroundings.
How does the first law apply to cell metabolism?
Cells transform energy from food into usable energy forms, but the total energy remains constant
What is an enzyme?
A protein that acts as a catalyst to speed up chemical reactions.
What are the products of ATP hydrolysis?
ADP (adenosine diphosphate) and an inorganic phosphate
What is a metabolic pathway?
It is a series of chemical reactions in a cell where a starting molecule is modified, step-by-step, to form a final product
Why is Earth an open system?
Because it receives energy from the sun and exchanges materials with space
How does the second law apply to cell metabolism?
Metabolic processes release heat, increasing the disorder in the universe.
What is activation energy?
The energy required to start a chemical reaction
What type of molecule is an enzyme?
A protein
How do cells regulate metabolic pathways?
Cells regulate metabolic pathways through enzymes that control the rate of reactions, often using feedback mechanisms.
What is our ultimate source of energy?
The Sun.
Can you explain the laws of thermodynamics in your own words?
The first law states that energy in the universe is constant, while the second law states that energy conversions are inefficient and increase disorder.
Differentiate between endergonic and exergonic reactions.
Endergonic reactions absorb energy and have positive free energy change, while exergonic reactions release energy and have negative free energy change
How does the structure of an enzyme relate to its function?
The specific shape of an enzyme allows it to bind to its substrate, facilitating the reaction.