Biology Lecture Review: Principles of Life

Comprehensive vocabulary flashcards covering biological principles, cellular structures, genetics, evolution, and ecology based on lecture notes.

Carbohydrates

Major source of energy including sugars and starches made of carbon, hydrogen, and oxygen with a $2:1$ ratio of hydrogen to oxygen.

Proteins

Nitrogen-containing compounds made of chains of $20$ different amino acids that compose enzymes, hormones, and antibodies.

Lipids

Water-insoluble fats and oils made of carbon, hydrogen, and oxygen composed of glycerol and fatty acids; they provide insulation and store energy.

Nucleic Acids

Molecules that direct protein instruction and genetic information, comprised of nucleotides which include a phosphate group, sugar, and nitrogenous base.

Chloroplast

Organelle found in plant cells and some algae that captures solar energy for photosynthesis.

Mitochondria

Organelles that transform energy through respiration.

Ribosome

Organelles responsible for producing proteins.

Prokaryote

An organism with nuclear material in the center of the cell not enclosed by a nuclear membrane and lacking membrane-bound organelles, such as bacteria.

Eukaryote

An organism containing a clearly defined nucleus enclosed by a nuclear membrane and membrane-bound organelles, found in plants, animals, fungi, and protists.

Cell Theory

The principle that the cell is the basic unit of life, all organisms are composed of cells, and all cells come from pre-existing cells.

Passive Transport

Movement of substances across the plasma membrane without using the cell's energy, following the concentration gradient.

Osmosis

The diffusion of water across the plasma membrane from areas of high concentration to areas of lower concentration.

Active Transport

Movement of substances across the plasma membrane from low to high concentration requiring the use of the cell's energy and carrier molecules.

Homeostasis

A self-regulating mechanism that maintains internal equilibrium and stable conditions within cells and organs.

Hypotonic

A solution concentration that causes water to move into the cell, potentially causing it to burst.

Hypertonic

A solution concentration that causes water to move out of the cell, causing it to shrivel.

Cellular Respiration

The process where food molecules are converted to energy: $C_6H_{12}O_6 + 6O_2 \rightarrow 6CO_2 + 6H_2O + \text{ENERGY (36 ATP)}$.

Photosynthesis

The process by which plant cells capture solar energy to convert it into food: $6CO_2 + 6H_2O + \text{ENERGY} \rightarrow C_6H_{12}O_6 + 6O_2$.

ATP (Adenosine Triphosphate)

A molecule that stores and releases energy in its bonds; energy is released when a phosphate group is removed to form $ADP$.

Fermentation

An anaerobic process that produces $ATP$ when oxygen is unavailable, resulting in Lactic Acid in muscle cells or Alcohol and $CO_2$ in plant cells.

Enzymes

Special proteins that act as catalysts to regulate biochemical reactions by lowering energy requirements without being used up.

DNA (Deoxyribonucleic acid)

A double-stranded twisted helix containing deoxyribose sugar and nitrogenous bases: adenine, thymine, guanine, and cytosine.

RNA (Ribonucleic acid)

A single-stranded nucleic acid containing ribose sugar and nitrogenous bases: adenine, uracil, guanine, and cytosine.

Transcription

The process where $mRNA$ is made from one strand of $DNA$ to carry a message to the ribosomes.

Translation

The process where $mRNA$ is translated into a protein at the ribosomes with the help of $tRNA$.

Mitosis

Nuclear division resulting in two daughter cells with the same number of chromosomes as the original cell ($2n = 46$ in humans).

Meiosis

Two-stage cell division that produces four haploid daughter cells ($n = 23$ in humans) with genetic variation, occurring only in sex cells.

Homozygous

A genetic condition where the two alleles of a pair are identical, such as $BB$ or $bb$.

Heterozygous

A genetic condition where the two alleles of a pair are different, such as $Bb$, often called a hybrid.

Genotype

The genetic makeup of an organism, represented by letters.

Phenotype

The physical appearance or description of an organism based on its genetic makeup.

Codominance

A pattern of inheritance where phenotypes of both homozygous parents are produced in heterozygous offspring, such as checkered chickens.

Incomplete Dominance

A pattern of inheritance where the phenotype of a heterozygote is intermediate between the two homozygous parents, such as pink flowers from red and white parents.

Natural Selection

The process proposed by Charles Darwin where organisms best suited to their environment survive and pass genetic traits to offspring.

Taxonomy

The branch of biology that deals with the grouping and naming of organisms.

Binomial Nomenclature

A two-name system developed by Linnaeus that gives each organism a genus and a species name.

Xylem

Vascular tissue in plants that transports water and minerals upwards from the roots.

Phloem

Vascular tissue in plants that transports sugars downwards from the leaves.

Mimicry

A structural adaptation that allows one species to resemble another species for protection from predators.

Mutualism

A symbiotic relationship in which both species benefit from the association.

Commensalism

A symbiotic relationship in which one species benefits and the other is neither harmed nor benefited.

Parasitism

A symbiotic relationship in which one organism benefits at the expense of another species, often causing disease.

Trophic Level

Each level in a food chain representing energy transfer; approximately $10\%$ of energy is transferred to the next level.

Primary Succession

The colonization of barren land by pioneer organisms where soil must first be developed.

Secondary Succession

The sequence of changes that take place after a community is disrupted by natural disasters or human actions, where soil is already present.