Introduction to Biology and Organic Molecules

Prokaryote

Simple, tiny cells without a nucleus.

Types of Prokaryotes

Includes Bacteria, Archaea, and Cyanobacteria.

Cyanobacteria

Earliest known prokaryotes, first to photosynthesize.

Aerobic Respiration

Energy production using oxygen, supports larger organisms.

Eukaryotic Cells

Larger, complex cells with a nucleus and organelles.

Multi-cellular Organisms

Evolved from eukaryotic cells, consist of many cells.

First Animals

Sponges and comb jellies were early animal forms.

Proto-Mammals

Warm-blooded mammals appeared 200 million years ago.

Non-Avian Dinosaur Extinction

Occurred 65 million years ago, mammals thrived afterward.

Cell Structure

Cells consist of atoms forming molecules and organelles.

Specialized Cells

Cells perform specific tasks in multicellular organisms.

Stimulus

Anything detectable by a life form.

Single-Celled Reproduction

Involves cell division and DNA copying.

Multi-Cellular Reproduction

More complex, offspring share traits with parents.

Adaptation

Organisms evolve to fit their environments.

Growth & Development

Organisms grow according to their genetic instructions.

Homeostasis

Maintaining stable internal conditions despite external changes.

Anatomical structure

Physical features like teeth and mouth shape.

Metabolism

Energy supply affects metabolic reaction speed.

Protons

Positively charged particles in an atom's nucleus.

Neutrons

Neutral particles in an atom's nucleus.

Electrons

Negatively charged particles orbiting the nucleus.

Element

Substance made of only one type of atom.

CHNOPS

Six elements making up 96% of living matter.

Isotopes

Atoms with the same protons, different neutrons.

Radioisotopes

Unstable isotopes that emit radiation.

Orbitals

Regions where electrons are found around the nucleus.

Valence electrons

Electrons in the outermost shell influencing reactivity.

Chemical bonds

Forces holding atoms together in molecules.

Ionic bonds

Transfer of electrons between atoms, forming charged ions.

Covalent bonds

Sharing of electron pairs between atoms.

Non-polar covalent bonds

Equal sharing of electrons between identical atoms.

Polar covalent bonds

Unequal sharing of electrons due to electronegativity differences.

Hydrogen bonds

Attraction between polar molecules involving hydrogen.

Hydrophilic

Substances that dissolve well in water.

Hydrophobic

Substances that do not dissolve in water.

Specific heat

Energy needed to raise 1g of water by 1°C.

Cohesion

Water molecules sticking together due to hydrogen bonds.

Adhesion

Water molecules sticking to solid surfaces.

Macromolecules

Large molecules made of smaller repeating units.

Functional groups

Specific groups of atoms influencing molecule properties.

Condensation reaction

Links monomers, releasing water in the process.

Hydrolysis reaction

Breaks bonds between monomers using water.

Amino acids

Building blocks of proteins, 20 different types.

Peptide bonds

Covalent bonds linking amino acids in proteins.

Primary structure

Sequence of amino acids in a protein.

Secondary structure

Folding of polypeptide chains due to hydrogen bonds.

Tertiary structure

3-D folding of protein influenced by R-groups.

Quaternary structure

Assembly of multiple polypeptide chains in proteins.

Denatured

Loss of protein's 3D structure due to disruption.

Chaperones

Proteins assisting in proper folding of other proteins.

Carbohydrates

Energy-rich molecules with general formula C#H2#O#.

Monosaccharides

Single sugar units, e.g., glucose.

Disaccharides

Two monosaccharides linked together.

Polysaccharides

Many monosaccharides linked, serving as energy storage.

Starch

Energy storage polysaccharide in plants.

Cellulose

Structural polysaccharide in plant cell walls.

Glycogen

Energy storage polysaccharide in animals.

Triglycerides

Fats and oils used for energy storage.

Phospholipids

Molecules forming cell membranes with hydrophilic heads.

Nucleic acids

Polymers for genetic information storage and transmission.

Nucleotides

Monomers of nucleic acids, consisting of sugar, phosphate, base.

Base pairing

Complementary pairing of DNA bases via hydrogen bonds.

DNA replication

Process of copying DNA before cell division.

Transcription

Making RNA copy from DNA.

ATP

Energy carrier for cellular reactions.