Basic Biochemistry - Vocabulary Flashcards

Vocabulary flashcards covering key concepts from the Basic Biochemistry notes to aid study and review.

States of matter

Solid – definite volume and shape; Liquid – definite volume but shape determined by container; Gas – no definite shape or volume.

Matter

Anything that occupies space and has mass.

Element

A fundamental substance that makes up all matter (e.g., H, He, O, C).

Compound

A substance composed of two or more elements joined by chemical bonds.

Major elements of the human body

Oxygen, Carbon, Hydrogen, Nitrogen, Calcium, Phosphorus, Potassium, Sulfur, Sodium, Chlorine, Magnesium (with Oxygen and Carbon as the most abundant by mass).

Trace elements

Minor minerals such as boron, chromium, cobalt, copper, fluorine, iodine, iron, manganese, molybdenum, selenium, silicon, tin, vanadium, and zinc.

Atom

The basic unit of matter consisting of protons, neutrons in the nucleus and electrons orbiting the nucleus.

Proton

Positively charged subatomic particle in the nucleus; mass ≈ 1 amu.

Neutron

Electrically neutral subatomic particle in the nucleus; mass ≈ 1 amu.

Electron

Negatively charged subatomic particle orbiting the nucleus; mass ≈ 1/2000 amu.

Atomic mass unit (amu)

Unit used to express atomic and subatomic masses; protons and neutrons ≈ 1 amu each; electrons ≈ 1/2000 amu.

Nucleus

Central region of an atom containing protons and neutrons.

Isotope

Atoms of the same element with different numbers of neutrons.

Heavy isotopes

Isotopes with more neutrons; often unstable and radioactive.

Energy

The capacity to do work or produce change; exists in many forms (kinetic, potential, etc.).

Kinetic energy

Energy of motion.

Potential energy

Stored energy due to position.

Chemical energy

Energy stored in chemical bonds; released or absorbed during reactions.

Thermal energy

Energy related to the temperature, i.e., the motion of particles (heat).

Mechanical energy

Energy due to the motion or position of an object.

Electrical energy

Energy of moving electric charges through a wire.

Magnetic energy

Energy associated with magnetic fields and forces.

Sound energy

Energy carried by sound waves that can be heard.

Light energy

Energy detected by the eyes as visible light.

Elastic energy

Stored energy in stretched or compressed objects.

Nuclear energy

Energy stored in the nucleus of atoms.

Gravitational energy

Energy stored due to an object's height above the earth’s surface.

Law of Conservation of Energy

Total energy in a closed system remains constant; it can change form or transfer between systems, but cannot be created or destroyed.

The Periodic Table

A tabular arrangement of elements organized by increasing atomic number and similar properties.

Element

A substance that cannot be broken down into simpler substances by chemical means.

Atomic number

Number of protons in the nucleus; defines the element.

Atomic symbol

One- to three-letter abbreviation for an element (e.g., H, O, Na).

Atomic mass/Atomic weight

Average mass of all isotopes of an element (weighted by abundance).

Isotope (periodic table context)

Variants of an element with different numbers of neutrons but same protons.

Electron orbitals (1s, 2s, 2p)

Regions around the nucleus where electrons are likely to be found; 1st shell holds up to 2 electrons, 2nd shell up to 8.

Electron-shell (valence) concept

Outer shell (valence shell) determines chemical reactivity; full valence shells lead to stability.

Valence shell

Outermost electron shell; full shells make atoms chemically inert.

Ions and bonds (basic)

Atoms can gain or lose electrons to form ions; ionic bonds form between oppositely charged ions.

Cation

A positively charged ion (loss of electrons).

Anion

A negatively charged ion (gain of electrons).

Ionic bond

A bond formed by electrostatic attraction between cations and anions; salts are often crystalline lattice structures.

Covalent bond

Bond formed by sharing electron pairs between atoms.

Single, double, triple covalent bonds

Different numbers of shared electron pairs: single (one pair), double (two pairs), triple (three pairs).

Nonpolar covalent bonds

Covalent bonds where electrons are shared equally between atoms.

Polar covalent bonds

Covalent bonds where electrons are shared unequally, creating partial charges.

Hydrogen bonds

Weak attractions between a hydrogen atom in one molecule and an electronegative atom in another (e.g., water).

Water as a solvent

Universal solvent; dissolves many substances and participates in hydrogen bonding.

Acids

Substances that release H+ ions in solution.

Bases

Substances that release OH- or accept H+ in solution.

pH

A measure of how acidic or basic (alkaline) a solution is; 7 is neutral. Lower values are more acidic, higher values more basic.

Buffers

Solutions that resist pH changes by neutralizing small amounts of added acid or base.

Carboxyl group

Functional group -COOH found in many organic acids.

Hydroxyl group

Functional group -OH found in alcohols and many biological molecules; polar.

Amino group

Functional group -NH2 found in amino acids.

Methyl group

Functional group -CH3; common in organic molecules.

Phosphate group

Functional group -PO4^3- or -PO4^2- found in nucleotides and phospholipids.

Carbohydrates

Biomolecules with C, H, and O; primary energy sources; include monosaccharides, disaccharides, and polysaccharides.

Monosaccharides

Simple sugars (e.g., glucose, fructose, galactose); hexoses (six-carbons) and pentoses (five-carbons like ribose, deoxyribose).

Disaccharides

Two monosaccharides linked (e.g., sucrose, lactose, maltose).

Polysaccharides

Many monosaccharides linked; examples include glycogen for energy storage.

Lipids

Molecules including triglycerides, phospholipids, steroids; mostly hydrophobic; energy storage and membrane structure.

Triglycerides

Neutral fats composed of glycerol esterified to three fatty acids.

Saturated fats

Fatty acids with no double bonds; typically solid at room temperature.

Unsaturated fats

Fatty acids with one or more double bonds; typically liquid at room temperature.

Phospholipids

Lipid with a polar head and nonpolar tail; major component of cell membranes.

Steroids

Lipids with four fused hydrocarbon rings; include cholesterol and steroid hormones.

Amino acids

20 different building blocks of proteins; each has a central carbon, an amino group, a carboxyl group, and a variable R group.

Peptide bonds

Covalent bonds linking amino acids in proteins via dehydration synthesis.

Protein structure levels

Primary, secondary (alpha-helix, beta-pleated), tertiary, quaternary; globular vs fibrous shapes.

Enzymes

Biological catalysts that speed reactions; lower activation energy without being consumed.

Nucleic acids

Biomolecules made of nucleotides; store and transmit genetic information.

Purines

Nucleobases A and G.

Pyrimidines

Nucleobases C, T (DNA), and U (RNA).

DNA vs RNA

DNA is double-stranded with A-T and C-G; RNA is single-stranded with A-U and C-G.

ATP

Adenosine triphosphate; primary energy currency of cells; contains three phosphate groups.