quizlet science

Science Quizlet Notes

Main Takeaway

  • The document summarizes diverse scientific facts covering fundamental concepts in human biology (anatomy, physiology, genetics, immunology), chemistry, and general science, often presented as definitions or short explanations suitable for quick review.

Human Anatomy & Physiology

Glands & Secretions

  • Salivary Glands:

    • Types: Parotid, Sublingual, & Submandibular glands.

    • Location: Roof of the mouth, cheeks, under the jawbone.

  • Kidneys:

    • Excrete Renin to regulate blood pressure.

    • Remove nitrogenous waste from the body.

    • Filter excess solutes from the blood.

    • Blood exits the glomerulus through the efferent arteriole.

    • Renal veins drain oxygen-depleted blood from the kidneys.

  • Sweat Glands: Excrete Urea in response to the breakdown of proteins and formation of ammonia.

  • Pancreas: Secretes Sodium bicarbonate which neutralizes the acidity of chyme.

  • Apocrine Gland: Secretes Pheromones (part of the integumentary system).

  • Exocrine vs. Endocrine Glands: Differentiated by the presence (exocrine) or absence (endocrine) of ducts.

Organs & Systems

  • Skin:

    • Largest organ in the human body by surface area.

    • Melanin protects the skin from ultraviolet radiation.

    • Epidermis lacks blood vessels.

  • Respiratory System:

    • Function: Exchange of gases between the body and environment.

    • Diaphragm: Dome-shaped muscle, responsible for regulating breathing rate and depth.

    • Alveoli: Respiratory structure affected by diseases that disrupt gas exchange (e.g., emphysema).

    • Pleura: Connective tissue sheath covering the lungs.

    • Pulmonary vein: Carries oxygenated blood.

  • Circulatory System:

    • Erythrocytes (Red Blood Cells): Primary function is the transportation of oxygen to body tissues.

    • Mitral Valve: Separates the left atrium and the left ventricle.

    • Myocardial Infarction: Affects the coronary vessels of the heart.

    • Diastole: The relaxation of the chambers of the heart during the cardiac cycle.

    • Endocardium: The tissue that lines the interior structures of the heart.

    • Blood flow from heart to an organ: Blood pumped from the heart first enters arteries, which then narrow to form arterioles that deliver blood to capillaries of the organ.

  • Nervous System:

    • Major Parts: Peripheral & Central nervous systems.

    • Motor Neuron: Responsible for releasing a neurotransmitter that stimulates muscle cells to contract.

    • Gray Matter: Largely made up of neuron cell bodies.

    • Ectoderm: The germ layer that forms the nervous system during embryonic development.

Digestive System

  • Breaks down proteins into amino acids.

  • Small Intestine: Aids in both digestion and absorption.

  • Lacteal Vessels: Lipids absorbed in the small intestine first enter these vessels.

Female Reproductive System

  • Corpus Luteum: Secretes hormones to maintain the uterine lining during pregnancy.

  • Fertilization of an egg cell occurs in the fallopian tube.

Tissues & Structures

  • Ligaments: Function is to attach two bones.

  • Vertebral Column (top to bottom): Cervical, Thoracic, Lumbar, Sacral, Coccygeal.

  • Joints:

    • Shoulder Joint: Allows for rotation of the arm at the shoulder.

    • Hip Joint: Ball and socket joint.

  • Muscles:

    • Isotonic Contractions: Produce movement.

    • Isometric Contractions: Produce no movement.

    • Role of Calcium in Muscle Contraction: Released from the sarcoplasmic reticulum to initiate sliding of actin and myosin filaments; binds to the troponin complex, initiating contraction.

    • Skeletal vs. Cardiac Muscles: Cardiac muscles contain intercalated discs, whereas skeletal muscles do not.

  • Bone:

    • Function: Storage of minerals.

    • Osteoporosis: Results from a decline in osteoblast activity while osteoclast activity continues at expected levels.

    • Tibia & Fibula: Found in the crural region of the body.

  • Vermiform Appendix: Extends from the region of the large intestine known as the cecum.

Hormones & Regulation

  • Renin: Regulates blood pressure.

  • Antidiuretic Hormone (ADH):

    • Synthesized by the hypothalamus gland.

    • Causes an increase in water reabsorption in the collecting duct.

  • Erythropoietin: Aids in raising hemoglobin levels in the blood.

  • Testosterone: An androgen hormone.

  • Pituitary Gland: Responsible for regulating milk production following childbirth.

  • Parathyroid Hormone: Regulates blood calcium level.

  • Cytokines: Chemicals released by one type of immune cell to directly activate another type of immune cell.

Other Physiological Facts

  • Mammalian neurons: Approximate threshold value for firing is $-55 ext{ mV}$.

  • Repolarization of a Neuron: Occurs due to the opening of potassium channels, allowing potassium to leave the neuron.

  • Psoriasis: A non-infectious disease.

  • Worm Infestation: Reduces the severity of certain autoimmune disorders.

  • Carbon Dioxide Movement: Most carbon dioxide from the blood moves into the alveoli via diffusion down a concentration gradient.

Biology

Cellular Biology

  • Cell Structures:

    • Cell Membrane: Structure present in both prokaryotic and eukaryotic cells.

    • Ribosomes: Synthesize proteins in the cell.

    • Centrosomes (Animal Cells): Main function is microtubule organization.

    • Cytoskeleton: Made up of proteins.

    • Lysosomes: The site of intracellular digestion.

    • Mitochondria: In the eukaryotic cell, it is responsible for making ATP.

    • Mitochondrial Inner Membrane: Carries out the same function as the Thylakoid membrane.

Cell Development

  • Totipotent Cell: Develops into any kind of cell.

  • During embryonic development, the ectoderm is the germ layer that forms the nervous system.

Osmosis

  • Definition: The movement of water molecules from high concentration to low concentration through a selectively permeable membrane.

  • Water flows through aquaporins embedded in the plasma membrane of the cell in a hypertonic solution.

Facilitated Diffusion

  • Definition: How water molecules enter cells.

Molecular Biology & Genetics

Protein Synthesis

  • tRNA (Transfer RNA): Responsible for carrying amino acids to ribosomes during protein synthesis.

Transcription

  • Definition: The process by which DNA is copied into RNA.

Sugars

  • Monosaccharides: Simple sugars that cannot be broken down.

  • Disaccharides: Composed of two simple sugars.

DNA

  • Genes: Used to determine a person's DNA sequence.

  • Chromatin: Contains a human's hereditary information.

  • Genetic Information: Describing organism characteristics is found in the nuclei.

Mutations

  • Frameshift Mutation: A type of genetic mutation that involves the insertion or deletion of one or more nucleotides in a DNA sequence.

  • If a mother's germ cell contains mutated DNA, it can be passed to her offspring.

Genetic Disorders

  • Down Syndrome: A genetic disorder caused by the presence of an extra chromosome 21.

RNA

  • Uracil: The nucleotide only found in RNA.

Proteins

  • Definition: Organic molecules that contain both an amine and a carboxyl group.

  • Classification: The class of biological molecules including enzymes.

  • Peptide Bonds: Covalent bonds between the monomers of an enzyme macromolecule.

  • Fibrinogen: Protein present in blood.

Biological Macromolecules

  • Types: Nucleic acid & protein.

Immunology

  • Innate Immunity:

    • Present at birth.

    • Provides immediate, non-specific protection.

  • Adaptive Immunity: Acquired after exposure to pathogens.

  • Plasma B Cells: The type of cells that produce and release antibodies.

  • Helper T-Cells: Stimulate other immune cells to attack and destroy foreign agents.

  • Perforins: Create holes in the cell membranes of their target cells to destroy the cell.

Microorganisms & Disease

  • Viruses:

    • Microorganisms that lack their own metabolic pathways and can only reproduce inside a host cell.

    • AIDS Virus: Contains RNA; uses Reverse transcriptase, an enzyme encoded by the virus, to insert viral DNA into the DNA of a host cell after entry.

    • Hypothesis: Genes that regulate cell division are found in some viruses, which could support the hypothesis that viruses can cause cancer.

Vaccines

  • Function: Expose the individual to a weakened or inactivated form of the pathogen.

Antibiotics

  • A doctor would say no to antibiotics for a cold sore or sore throat if the illness is caused by a virus.

Emphysema

  • Cause: Damage to alveoli from toxins and pollutants, likely to result in difficulty exchanging oxygen and carbon dioxide.

Cancer

  • Definition: A genetic mutation that results in uncontrolled division of a single cell within the body.

Plant Biology

  • Chlorophyll a: The primary pigment responsible for photosynthesis in plants.

Chemistry

Properties & Changes

  • Chemical Property: Reactivity with acid.

  • Chemical Change: Rearrangement of atoms and the formation of new substances with different chemical properties (e.g., burning wood).

  • Exothermic Reaction: Burning wood is an example.

  • Reaction with Water: Water produces gas with sodium metal.

Atomic Structure & Bonding

  • Atomic Number: The number of protons in an atom.

    • An atom that has 12 protons and 12 neutrons has an atomic number of 12.

    • Lithium has an atomic number of 3 and a mass of 7, so the number of protons is 3.

  • Electron: The component of an atom that possesses relatively little mass, thus being negligible in calculating the atomic mass.

  • Ions:

    • A chloride ion has a negative charge because it gained an electron.

    • An atom like fluorine (atomic #9) is most likely to become a cation.

  • Covalent Bonds:

    • Nitrogen gas is extremely stable because of triple covalent bonds.

    • Chlorine would contain the fewest covalent bonds (likely referring to the diatomic molecule Cl2Cl_2).

  • Molecular Geometry: The molecular geometry of a molecule of sulfur dioxide (SO2SO_2) is bent.

  • Proton Emission: If an atom has mass number AA and atomic number ZZ (represented as "2" in the input), after a proton is emitted from its nucleus, the new mass number is A−1A-1 and the new atomic number is Z−1Z-1.

pH & Buffers

  • pH: Defined as −extlog[H+]- ext{log}[H^+].

    • A solution with a hydrogen ion concentration ([H+])([H^+]) of 10−110^{-1} M has a pH of 1.

    • A solution with a hydrogen ion concentration ([H+])([H^+]) of 10−910^{-9} M has a pH of 9.

    • A substance with a pH of 3 is 10 times more acidic than a substance with a pH of 4.

    • A hydrogen-ion concentration of pH 4 is 100,000 stronger compared to one with pH 9 (109−4=10510^{9-4} = 10^5).

  • Carbonic Acid: Responsible for donating H+H^+ ions to act as a buffer when blood pH rises.

States of Matter

  • Triple Point: A substance held at a temperature and pressure where the solid, liquid, and gas states of a substance exist simultaneously.

Oxidation

  • Oxidation Reaction: Involves the removal of electrons.

Water Polarity

  • Polarity of Water Molecules: Explains its solvent abilities for certain substances.

  • Soap's Dual Polar and Nonpolar Nature: Helps bond oil and water, making it possible to wash dirt off hands.

General Science & Research

Research & Data Analysis

  • Traffic Pattern Analysis: Data collected on cars passing through an intersection would be most useful to analyze traffic patterns during rush hour.

  • Control Group: Can be measured against the experimental group.

  • Hypotheses: Experiments cannot validate hypotheses, only falsify them; a hypothesis that has not been falsified remains provisional.

Physics Concepts

  • Heavier Objects Fall Faster: Heavier objects fall faster than lighter ones. (Note: This statement contradicts the principle that in a vacuum, all objects fall at the same rate due to gravitational acceleration.)