Comprehensive Biology Foundations Flashcards

A collection of vocabulary-style flashcards based on lecture notes covering molecular biology, metabolism, genetics, physiology, and evolution.

Glycosidic bonds

Bonds that join carbohydrates together via a dehydration reaction.

Secondary protein structure

Intermolecular forces between polypeptide backbones due to hydrogen bonding, specifically forming a-helices and B-pleated sheets.

Phosphatase

An enzyme that cleaves a phosphate group off a substrate molecule.

Competitive inhibition

A form of enzyme inhibition where $K_m$ increases (substrate concentration at $50$% of max reaction velocity) and $V_{max}$ (maximum reaction velocity) stays the same.

Triglyceride

A lipid composed of a glycerol backbone and three fatty acids connected by ester linkages.

Phosphodiester bonds

Bonds formed during condensation where the 5' phosphate group of one nucleotide attaches to the 3' hydroxyl group of another, releasing water.

Endosymbiotic theory

The theory that eukaryotes developed when aerobic bacteria were internalized as mitochondria while photosynthetic bacteria became chloroplasts.

Secondary active transport

Transport that uses energy from one molecule moving down its gradient to drive the transport of another molecule against its gradient.

Gap junctions

Cell-to-cell junctions in animal cells that allow the passage of ions and small molecules between cells.

Glycolysis

A metabolic process in the cytosol where glucose is converted into $2$ ATP, $2$ NADH, and $2$ pyruvate.

Facultative anaerobes

Organisms that can perform aerobic respiration, anaerobic respiration, or fermentation, but prefer aerobic respiration because it produces the most ATP.

Glycogenolysis

The release of glucose-6-phosphate from glycogen.

Thylakoids

Membrane structures within the stroma where light-dependent reactions occur; multiple thylakoids stack to form a granum.

Photorespiration

A process that produces a two-carbon phosphoglycolate, which is then converted into PGA ($C_2$ photosynthesis).

Germ cells

Diploid cells that divide by mitosis and differentiate into gametocytes.

S-phase (Synthesis phase)

The phase of interphase where the cell replicates its genome and the centrosome duplicates.

Synapsis

The pairing of homologous chromosomes to form tetrads during Prophase I of meiosis.

Topoisomerase

An enzyme that nicks the DNA double helix ahead of helicase to relieve supercoiling during replication.

Lac operon

An inducible operon where the lac repressor protein is removed from the operator only when lactose is converted to allolactose.

Splicing

A eukaryotic post-transcriptional modification process where introns are removed from pre-mRNA by spliceosomes.

Epistasis

A pattern of inheritance where one gene affects the expression of a different gene.

Nondisjunction

The improper segregation of chromosome pairs during anaphase, resulting in daughter cells with an incorrect number of chromosomes.

SDS (Sodium Dodecyl Sulfate)

A detergent used in protein gel electrophoresis to denature proteins and add a negative charge, allowing separation by size.

Xylem

Plant tissue that transports water and dissolved minerals from the roots (source) to the leaves (sink).

Bohr effect

The phenomenon where hemoglobin's oxygen affinity decreases when $CO_2$ levels are high, leading to the formation of reduced hemoglobin.

Complement system

A group of $30$ proteins that aid immune cells by tagging antigens for phagocytosis, amplifying inflammatory responses, and forming membrane attack complexes.

Saltatory conduction

The process where action potentials jump between nodes of Ranvier (gaps in the myelin sheath) to speed up signal transmission.

Troponin

The protein that binds calcium ions, leading to the removal of tropomyosin from actin filaments to allow muscle contraction.

Osteoclasts

Cells that resorb or 'eat' bone, stimulated by parathyroid hormone (PTH) to increase blood calcium levels.

Tropic hormones

Hormones released by the anterior pituitary (such as FSH, LH, ACTH, and TSH) that target other endocrine glands for hormone release.

Bile

A substance produced in the liver and stored in the gallbladder that aids in the digestion of fats.

Juxtaglomerular cells

Cells in the kidney that release renin when blood pressure is low, initiating the Renin Angiotensin Aldosterone System (RAAS).

Gastrulation

The formation of a gastrula where cells invaginate to create three germ layers: endoderm, mesoderm, and ectoderm.

Allopatric speciation

The formation of new species due to the presence of a geographical barrier.

Keystone species

A species that maintains ecological balance in an ecosystem despite its low relative abundance.