BIOL 3134 Cell and Molecular Biology Flashcards

Vocabulary flashcards covering key chemical bonds, biological small molecules, macromolecules, mitochondrial electron transport complexes, and fundamental cell biology concepts for BIOL 3134.

Covalent Bond

A strong chemical bond formed by the sharing of electrons between atoms.

Ionic Bond

A chemical bond formed by the transfer (gain and loss) of electrons between atoms, where opposite charges hold the resulting ions together.

Hydrogen Bond

An important noncovalent interaction formed between partial positive ($\delta^+$) and partial negative ($\delta^-$) charges, such as between water molecules.

Noncovalent Bonds

Weaker interactions in water than covalent bonds that help bring molecules together, allow macromolecules to bind selected molecules, and specify macromolecular shape.

Sugars (Monosaccharides)

Small organic building blocks of the cell that serve as energy sources and subunits for polysaccharides, glycogen, and starch.

Polysaccharides

Larger organic molecules formed from sugar subunits, used by cells for energy storage and structural support.

Fatty Acids

Small organic building blocks consisting of long, almost always straight chains of carbon and hydrogen, used as components of cell membranes and fats.

Lipid Bilayer

A membrane structure composed of phospholipids with hydrophilic phosphate heads and hydrophobic fatty acid tails.

Amino Acids

Small organic building blocks with an identical repeating backbone and distinct side chains (R-groups) that serve as the subunits of proteins.

Polypeptide Chain

A polymer of amino acids joined together with directionality, featuring an N-terminus at one end and a C-terminus at the other.

Nucleotides

Small organic building blocks consisting of a phosphate group, a five-carbon sugar (ribose or deoxyribose), and a nitrogenous base, serving as subunits of nucleic acids and energy carriers.

Nucleic Acids

Larger organic molecules (such as DNA and RNA) built from nucleotide subunits with directional 3' and 5' ends that store genetic information.

ATP (Adenosine Triphosphate)

A nucleotide activated carrier containing high-energy phosphoanhydride bonds that transfers energy from food or sunlight to power intracellular work and chemical synthesis.

NADH Dehydrogenase Complex

An inner mitochondrial membrane protein complex that accepts electrons from NADH, removes protons ($\text{H}^+$), and pumps protons across the membrane.

Ubiquinone and Cytochrome c

Mobile electron carriers in the mitochondrial electron transport chain that shuttle electrons between major protein complexes.

Cytochrome c Reductase Complex

A mitochondrial membrane complex that donates electrons to cytochrome c (reducing cyt c) and pumps protons ($\text{H}^+$).

Cytochrome c Oxidase Complex

A mitochondrial membrane complex that accepts electrons from cytochrome c (oxidizing cyt c), combines 4 electrons with $\text{O}_2$ to form $2\,\text{H}_2\text{O}$, and pumps protons ($\text{H}^+$).

First Law of Thermodynamics

The physical law stating that energy cannot be created or destroyed.

Second Law of Thermodynamics

The physical law stating that entropy (disorder) in an isolated system always increases.

Prokaryotes

The most diverse and numerous single-celled organisms on Earth, divided into two domains: Bacteria and Archaea.

Eukaryotes

Cells characterized by a membrane-bound nucleus and internal membrane-bound compartments (organelles) such as mitochondria, chloroplasts, and the cytosol.

Phosphodiester Bond

The covalent bond linking nucleotides together in a nucleic acid chain between the 3' and 5' positions.