Energy and Enzymes

This set of flashcards focuses on the key concepts, definitions, and principles related to energy and enzymes in the context of biology.

What are the two major types of energy?

Potential and kinetic energy.

What does the first law of thermodynamics state?

Energy cannot be created or destroyed, only transformed.

What is Gibbs free energy (G)?

amount of energy for work / ΔG

thermodynamics 2nd law

energy transformation increase disorder/ release heat

What do exergonic reactions do?

spontaneous

release energy

product has less energy than reactant

breaking down things

negative ΔG

What do endergonic reactions do?

absorb (take in) energy

non spontaneous

building things (like new bonds)

positive ΔG

products have more energy than reactants

What is energy coupling?

Using the energy released from exergonic reactions to power endergonic reactions.

What is activation energy (EA)?

this is a barrier/obstacle for chemical reaction

slows down chemistry

applies to all chemical reactions (endorgonic + exergonic)

What is the role of enzymes in chemical reactions?

biological catalysts that speed up chemical reactions

how do enzymes speed up chem reactions

they lower activation energy of reaction

how do enzymes lower activation energy of reaction

1) hold substrate in certain orientation

2) weaken covalent bonds in substance

force substrate to look like transition state (induced fit)

most enzymes are proteins

substrates = reactant for enzyme (catalyze reaction)

enzymes are specific for their substrates back on shape (of active site)

induced fit

enzyme “folds” around substrate when bound (forces substrate to resemble transition state)

enzymes are affected by..

environmental changes (temp,ph,salt)

phosphorylation

can lead to denaturation and loss of enzyme activity

steps of enzyme catalysis

1) substrate and enzymes bind

2) chemical reaction is catalyzed (bonds broken or formed)

3)products are released, enzyme active site is open

What is the difference between cofactors and coenzymes?

Cofactors are non-protein helpers, while coenzymes are organic cofactors like vitamins.

phosphorylation (inactive to active)

reaction that involves addition of phosphate group (covalent bond formed)

dephosphorylation (active to inactive)

What defines metabolic pathways?

A series of linked reactions to form a product.

What is the difference between anabolic and catabolic pathways?

anabolic- small to large / building /add energy (endergonic)

catabolic - large to small/ breaking apart / release energy (exergonic)

metabolism

total chemical reactions that occur in organism

What does the term 'induced fit' refer to in enzyme function?

The active site's shape changes to fit the substrate better, enhancing the reaction.

potential energy

stored energy

concentration gradient / chemical energy

kinetic energy

energy of movement

ex heat