Biology Lecture: Macromolecules, Cell Structure, and Cell Theory

Vocabulary flashcards covering key biological concepts, macromolecules, cellular components, and cell types discussed in the lecture.

Macromolecules

Molecules composed of multiple units connected together to form a polymer.

Nucleotides

The subunits of nucleic acids, consisting of a phosphate group, a sugar, and a nitrogenous base.

Nitrogenous Bases

The components of a nucleic acid attached to the sugar-phosphate backbone whose specific order conveys genetic information.

RNA

A single-stranded nucleic acid molecule.

DNA

A nucleic acid molecule composed of two strands connected together by hydrogen bonds between complementary bases.

Amino Acids

The building block subunits that link together to form proteins.

R Group

The variable portion of an amino acid's structure that differs among the $20$ amino acids found in living things and determines its specific identity.

Sickle Cell Anemia

A genetic disease caused by a mistake in the amino acid sequence of hemoglobin, resulting in misshapen red blood cells that carry oxygen inefficiently and block blood vessels.

Hemoglobin

A protein located in red blood cells that carries oxygen throughout the blood.

Telomere

A repeating, non-protein-coding section of DNA at the end of a chromosome that gets shorter each time a cell copies its DNA.

Enzymes

Proteins that dramatically speed up chemical reactions and reduce the amount of energy required to start those reactions.

Cytoskeleton

A structural framework of proteins inside the cell that provides support and holds cellular components together.

Fatty Acids

Lipid molecules consisting of long strings of carbon atoms bonded to each other and mostly attached to hydrogen atoms.

Phospholipids

Lipids consisting of a hydrophilic polar phosphate head attached to two hydrophobic nonpolar fatty acid tails, forming cellular membranes.

Steroids

A group of lipids characterized by a fused ring structure consisting of three hexagons and one pentagon, which often function as hormones or membrane stabilizers.

Cell Theory

The fundamental principle stating that all living things are composed of cells, the cell is the basic unit of life, all cells come from pre-existing cells, and all energy flow in living things occurs through cells.

Prions

Misfolded proteins that cause other proteins to misfold; they are not made of cells or contained within a membrane.

Prokaryotes

Small, simple cells that lack a nucleus and membrane-bound internal compartments.

Eukaryotes

Larger, complex cells that contain a true nucleus and internal membrane-bound compartments called organelles.

Archaea

A group of single-celled prokaryotic organisms that frequently inhabit extreme environments like volcanic springs, high-methane conditions, or extreme salt.

Protists

A kingdom of eukaryotic single-celled, non-photosynthetic organisms, such as amoebas and slime molds.

Chromista

A kingdom of photosynthetic eukaryotic organisms that are not plants, including kelp, seaweed, and various microscopic photosynthetic species.

Plasma Membrane

A cellular membrane composed of a phospholipid bilayer, cholesterol, and proteins that separates the cell's interior from its external environment.

Cytoplasm

The internal liquid environment of a cell that maintains suitable chemical composition and pH for cell functions.

Ribosomes

Cellular structures found in all cells where proteins are synthesized.

Fluid Mosaic Model

A structural model describing the plasma membrane as a flexible, fluid layer of moving phospholipids interspersed with cholesterol and proteins.