Chemistry Lecture 2 Flashcards
1
Q
Isotopes
(radioactive isotopes)
A
Unstable isotopes decay, causing radioactivity.
Examples: uranium & plutonium.
2
Q
Half-Life
A
- Half-life = time for half of isotopes to decay.
- Carbon-14 for carbon dating.
3
Q
Free Radicals
A
- Unpaired electron in outer shell.
- Produced in metabolism, can damage body.
- Removed by Enzymes, Antioxidants.
- Causes cellular damage via oxidation.
- Leads to OXIDATIVE STRESS, chronic diseases.
4
Q
Energy in Chemical Reactions
Energy, Potential, Kinetic
A
- Energy: capacity to do work.
- Potential energy: stored by matter due to position.
- Kinetic energy: associated with motion.
5
Q
Exergonic Reactions
A
- Energy released to surroundings.
- Bonds formed stronger than those broken.
- More energy released than absorbed.
- Examples: Digestion, Glycolysis.
6
Q
Endergonic Reactions
A
- Energy absorbed from surroundings.
- Bonds formed weaker than those broken.
- Require more energy than released.
- Examples: Synthesis reactions.
7
Q
Activation Energy
A
- Initial energy for chemical reactions.
- Allows efficient energy use.
- Energy conserved, not destroyed.
8
Q
Metabolism
A
- Body’s chemical reactions.
- Affected by diet, exercise, genes.
- Two categories: Anabolic, Catabolic.
9
Q
Anabolism
A
- Anabolic reactions: small → large molecules.
- Uses energy, endergonic.
- A + B + energy → AB.
- Anabolism powered by catabolism.
10
Q
Catabolism
A
- Catabolic reactions: large → small molecules.
- Releases energy, exergonic.
- AB → A + B + energy.
11
Q
Hydrolysis
A
- Type of decomposition reaction involving water.
- Breaks one bond in a molecule.
- Components of water added to fragments.
- Majority of body’s catabolic reactions.
12
Q
Exchange Reactions
A
- Cations and anions switch partners.
- Products remain electrically neutral.
- AB + CD → AD + BC.
13
Q
Reversible Reactions
A
- Constantly shifting between reactants/products.
- Equilibrium: rate of each reaction equal.
14
Q
Oxidation-Reduction Reactions
A
- Essential for breaking down food for energy.
- Electron transfer between atoms/molecules.
- Oxidation: loss of electrons, energy released.
- Reduction: gain of electrons, energy absorbed.
