Lab Equipment and Scientific Method

Lab Equipment

• Accuracy is how close a measured value is to the true value.
• Precision is how close measured values are to each other.
• The meniscus is the curve of a liquid at the surface, where it touches another material.
• Beaker: used for stirring, mixing and transferring solutions.
• Flask: used for reactions or mixing/heating.
• Graduated cylinder: has measurement lines, more precise than beakers for measuring small volumes.
• Pipettes: transfer fluids, can be graduated for precise measurements.
• Aspirate: to draw up a sample.
• Dispense: to deliver a sample.
• Blow-out: empty the tip completely after using a pipette.

Science and the Scientific Method

• Science is an active, dynamic, and objective process of gathering and organizing information about the natural world.
• Goal of Science: gain knowledge about the natural world.
• Modern Scientific Research: often goal-directed (applied technology).
• Hypothesis: an explanation limited in scope, based on prior knowledge.
• Theory: a powerful, broad explanation supported by extensive testing and accurate predictions about phenomena. No scientific idea is ever completely "proved"
• Science: focuses on natural explanations, not opinions, judgments, beliefs, or supernatural phenomena. It doesn't make moral judgments.

Microscopy and Cell Types

• Cell Theory: all life is composed of cells, cells are functional units of life, and all cells come from pre-existing cells.
• Scanning electron microscope (SEM): visualizes cell surfaces, requiring a thin metal coating; produces high-resolution, 3-D images.
• Transmission electron microscope (TEM): visualizes internal cell structures; produces high-resolution, 2-D images.
• 3-part Cell Theory: All life is composed of cells, cells are the functional units of life, and all cells come from pre-existing cells

Organic Molecules

• Organic molecules contain carbon, often with hydrogen. Some examples include: methane, carbohydrates, proteins, fats, and nucleic acids (DNA/RNA).
• Monomers: single units of carbohydrates, proteins, and nucleic acids.
• Polymers: formed from joining monomers.
• Carbohydrates include simple sugars and polysaccharides.
• Monosaccharides: simple sugars; building blocks of carbohydrates.

Membrane Transport

• Passive transport: no energy required across a membrane; includes simple diffusion, osmosis.
• Diffusion: movement of particles from areas of high concentration to low concentration.
• Osmosis: diffusion of water across a semi-permeable membrane.
• Aquaporins: special water channels in cell membranes.
• Active transport: requires energy to move substances across a membrane against the concentration gradient. includes exocytosis and endocytosis.

Cellular Respiration

• Cellular respiration: organisms extract & put potential energy from glucose, into ATP.
• Glycolysis: glucose is split in half, some energy transferred to electrons.
• Krebs Cycle: The Krebs cycle is where pyruvate's derivative is oxidized; and some energy is transferred to electrons
• Electron Transport Chain: electrons' energy forms ATP. Oxygen is the final acceptor of electrons.

Photosynthesis

• Photosynthesis: autotrophs capture light energy and use it to produce glucose.
• Chlorophyll: pigment that absorbs light energy for photosynthesis.
• Auxiliary pigments: (carotenoids, anthocyanins) absorb light in different ranges.
• Photosystems: large protein structures in the thylakoid membrane that harvest light energy.
• Stages: light reactions and Calvin cycle.

DNA, Cell Cycle, and Mitosis

• DNA stores instructions. A cell cycle progresses from start to finish of one cell division, to the next. Key phases are mitosis and interphase.
• Cell theory: All cells come from pre-existing cells.
• Main components of a nucleotide: five carbon sugar, phosphate group, and a nitrogenous base.
• Different types of Nitrogenous bases: Purines (adenine/guanine), pyrimidines (thymine/cytosine); and Uracil, a pyrimidine, is used in RNA.
• RNA: contains uracil (U) instead of thymine for its nitrogenous base composition.

Cell Division (Meiosis/Mitosis)

• Meiosis: cell division to form gametes (sex cells); reduces the chromosome number to half.
• Mitosis: cell division (somatic cell division) that results in two identical daughter cells; for growth & repair.
• Gametes: haploid sex cells (egg and sperm).
• Zygote: fertilized egg (diploid); first cell of new organism.
• Homologous chromosomes: matched pairs of chromosomes with similar gene order and location.

Genetics and Inheritance

• Homozygous: having two identical alleles for a gene.
• Heterozygous: having two different alleles for a gene.
• Dominant allele: expressed in the heterozygote.
• Recessive allele: masked in heterozygote.
• Complete Dominance: one allele is fully dominant over another.
• Mendelian Ratio: the phenotypic ratio of 3:1 observed in the offspring generation of a monohybrid cross.
• Principle of Segregation: each allele for a trait separates during gamete formation.
• Principle of Independent Assortment: alleles for one trait separate independently of alleles for other traits during gamete formation.
• Phenotype is a visible trait (actual appearance).
• Genotype is a set of alleles that form the gene (the genetic code).
• Karyotyping: used to study chromosomal abnormalities and arrange based on size.

Test your knowledge of lab equipment and the scientific method! This quiz covers important concepts such as accuracy, precision, and various types of lab tools like beakers and pipettes. Additionally, it explores the foundational aspects of scientific inquiry and research methodology.