Bio Sci 93 notes

Atoms

Atoms

The smallest units of chemical elements, made up of protons, neutrons, and electrons.

Molecules

Two or more atoms bonded together.

Compounds

Molecules made from two or more different elements in a fixed ratio.

Covalent bonds

Bonds involving the sharing of electrons between atoms.

Ionic bonds

Bonds involving the transfer of electrons between atoms.

Hydrogen bonds

Weak interactions where a hydrogen atom covalently bonded to one atom forms a second, weaker bond with an electronegative atom of another molecule.

Cohesion

The property of water where water molecules form hydrogen bonds with each other.

Solvent Properties

Water's ability to dissolve various substances due to its polarity.

Hydrophilic

Substances that are attracted to water and can form hydrogen bonds.

Hydrophobic

Substances that repel water and tend to have nonpolar bonds.

pH Scale

Measures the acidity or basicity of a solution; a lower pH means more acidic, while a higher pH means more basic.

Buffers

Systems that help maintain a stable pH in biological systems by donating H⁺ or accepting OH⁻ as needed.

Carbon

The foundational element of organic molecules, capable of forming stable covalent bonds due to its four valence electrons.

Monosaccharides

Simple sugars, which are the building blocks of carbohydrates.

Polysaccharides

Long chains of monosaccharides that serve energy storage and structural roles.

Phospholipids

Lipid molecules vital for cell membranes, consisting of glycerol, two fatty acids, a phosphate group, and choline.

Proteins

Macromolecules made of amino acids linked by peptide bonds, involved in various cellular functions.

DNA

A nucleic acid that carries genetic information and consists of two strands of nucleotides wound into a double helix.

Cellular Respiration

The catabolic process that generates ATP by breaking down glucose and other macromolecules.

Photosynthesis

The process through which autotrophs convert light energy into chemical energy, producing glucose and oxygen.

Aneuploidy

A condition where an organism has an abnormal number of chromosomes due to errors in meiosis.

Gene Linkage

The tendency for genes located close to each other on the same chromosome to be inherited together due to physical proximity.

Epigenetics

The study of heritable changes in gene expression that do not involve alterations to the DNA sequence.

Differentiation

The process through which unspecialized cells become specialized in structure and function to perform specific tasks.

Morphogenesis

The process through which cells develop their shape and organize into tissues, organs, and structures.

Transcription Factors

Proteins that help regulate gene expression by binding to specific DNA sequences.

Neurotransmitter

Biochemicals that transmit signals across a synapse from one neuron to another.

CRISPR-Cas9

A gene-editing technology that allows precise modification of DNA using RNA-guided DNA cutting.

Stem Cells

Unspecialized cells with the ability to differentiate into specialized cells and divide indefinitely.

Genomic Imprinting

A form of epigenetic inheritance where gene expression depends on whether the allele is inherited from the mother or father.