Biology Vocabulary from Lecture Notes: Photosynthesis, Entropy, and Bonding

A vocabulary-style set of flashcards covering key concepts from the lecture notes on photosynthesis, atmosphere evolution, hypothesis testing, entropy, and atomic bonding.

Photosynthesis

The set of chemical reactions that transforms energy from the sun into chemical bond energy (ATP and NADPH) used to power cellular processes.

Aerobic metabolism

Metabolic processes that require oxygen and yield more energy compared to anaerobic pathways.

Oxygen

A chemical element essential for aerobic metabolism; its accumulation contributed to the formation of the ozone layer.

Ozone

A protective layer formed from oxygen that shields living things from harmful UV radiation.

Entropy

A measure of disorder in a system; systems tend toward increased disorder over time.

Hypothesis

A testable explanation or educated guess that can be supported or refuted by experiments.

Observation

Data or information gathered through the senses or instruments to study phenomena.

Primary production

The rate at which photosynthetic organisms convert inorganic carbon into organic matter.

Chlorophyll biomass

The amount of chlorophyll in a given area, indicating potential for photosynthesis.

Metabolism

All chemical processes that occur within a living organism to sustain life.

Atom

The basic unit of matter consisting of a nucleus (protons and neutrons) surrounded by electrons.

Proton

A positively charged subatomic particle located in the atom’s nucleus.

Neutron

An electrically neutral subatomic particle located in the nucleus.

Electron

A negatively charged subatomic particle that orbits the nucleus and participates in bonding.

Nucleus

The center of an atom that contains protons and neutrons.

Atomic number

The number of protons in an atom’s nucleus; determines the element’s identity.

Mass number

The total number of protons and neutrons in the nucleus.

Electron shell

Regions around the nucleus where electrons reside; shells have capacity limits.

Valence electrons

Electrons in the outermost shell that determine bonding behavior and stability.

Ionic bond

A bond formed by transfer of electrons from one atom to another, creating oppositely charged ions.

Covalent bond

A bond formed by sharing electrons between atoms.

Polar covalent bond

A covalent bond where electrons are shared unequally, creating partial charges.

Nonpolar covalent bond

A covalent bond where electrons are shared nearly equally, producing no strong dipole.

Electronegativity

A measure of how strongly an atom attracts electrons in a bond.

Hydrogen bond

A weak attraction between a partially positive hydrogen atom and a highly electronegative atom, crucial in water and biomolecules.

Van der Waals interactions

Weak, transient forces between molecules due to temporary dipoles.

Water polarity

Water’s uneven charge distribution makes it a polar solvent with strong hydrogen-bonding capacity.

Functional group

A specific group of atoms within a molecule that imparts characteristic reactivity.

Hydroxyl group

An -OH group; a polar covalent functional group found in alcohols.

Alcohol

An organic compound containing a hydroxyl (-OH) group.

Ester bond

A covalent bond formed between a carbonyl carbon and an oxygen atom, common in lipids.

Phosphate group

A phosphorus-containing group important in energy transfer (ATP) and nucleic acids.

Carbon

A central element in organic molecules that forms four covalent bonds; tetravalent.

Hydrogen (as an element in bonding)

A simple element that forms bonds and participates in molecular structures.

Nitrogen

An element with valence typically three, common in amino groups and nucleotides.

Oxygen

An highly electronegative element with valence two, essential in water and organic molecules.

Phosphorus

An element essential for energy transfer (ATP/ADP) and nucleic acids.

Sulfur

An element in some amino acids; forms disulfide bonds and contributes to protein structure.