Untitled Quiz

Chemical Processes

• Anabolic reactions build complex molecules from simpler ones, requiring energy (often ATP). Examples include protein synthesis.
• Catabolic reactions break down complex molecules into simpler ones, releasing energy. An example is cellular respiration (glucose breakdown).
• Dehydration reactions (condensation reactions) join molecules by removing a water molecule. An example is the formation of a disaccharide from two monosaccharides.
• Hydrolysis reactions break down molecules by adding a water molecule. An example is the breakdown of a disaccharide into two monosaccharides.

Protein Structure

• Primary structure: The sequence of amino acids in a polypeptide chain. This sequence determines the protein's properties and function.
• Secondary structure: Local folding of the polypeptide chain into structures like alpha-helices and beta-sheets, stabilized by hydrogen bonds.
• Tertiary structure : The overall 3D structure of a single polypeptide chain, formed from interactions (hydrophobic, ionic bonds, disulfide bridges).
• Quaternary structure: The structure formed by multiple polypeptide chains coming together (e.g., hemoglobin).

Factors affecting Protein Structure

• Temperature: High temperatures can disrupt hydrogen bonds, leading to denaturation.
• pH: Changes in pH affect ionization of amino acid side chains, disrupting bonds.
• Salt concentration: High salt can interfere with ionic and hydrogen bonds.
• Chemical agents: Chemicals like urea and detergents can disrupt various bonds, causing denaturation.
• Genetic mutations: Changes in DNA sequence can lead to changes in the amino acid sequence, potentially affecting protein structure and function.

Acids, Bases, and Buffers

• pH: A measure of hydrogen ion concentration ([H+]) in a solution (range 0-14). A pH of 7 is neutral; <7 is acidic, and >7 is basic.
• Acids: Substances that increase [H+] in a solution.
• Bases: Substances that reduce [H+] (often increasing [OH-]).
• Buffers: Solutions that resist changes in pH when acids or bases are added, maintaining stable pH. Examples include weak acids and their conjugate bases or weak bases and their conjugate acids.

Water Properties

• Cohesion: Water molecules stick together due to hydrogen bonding. This leads to surface tension.
• Adhesion: Water molecules stick to other substances (e.g., capillary action).
• High specific heat: Water can absorb a lot of heat before its temperature rises, moderating climates.
• High heat of vaporization: Water requires a significant amount of energy to change from liquid to gas, allowing for effective cooling.
• Density: Water is most dense at 4°C, and it expands as it freezes, making ice less dense than liquid water.

Chemical Bonds

• Ionic bonds: Formed by the transfer of electrons between atoms, creating oppositely charged ions attracting each other.
• Covalent bonds: Formed by sharing pairs of electrons between atoms.  Varying electron sharing creates polar or nonpolar bonds.
• Hydrogen bonds: Weak attractions between a hydrogen atom in one molecule and an electronegative atom (O or N) in another molecule.
• Van der Waals forces: Weak attractions between molecules due to temporary fluctuations in electron distribution.

Isomers

• Structural isomers (constitutional isomers): Same molecular formula, different atom connectivity.
• Geometric isomers (cis-trans isomers): Same molecular formula and connectivity, different spatial arrangements due to restricted rotation around a double bond or ring.
• Optical isomers (enantiomers): Non-superimposable mirror images of each other, differing in how they rotate plane-polarized light.

DNA

• DNA is deoxyribonucleic acid, a molecule that holds genetic instructions.
• Contains nucleotides with a phosphate group, deoxyribose sugar, and nitrogenous bases (A, T, C, G).
• Forms a double helix with antiparallel strands and complementary base pairing (A-T, C-G).

Fats

• Saturated fats: Have no double bonds between carbon atoms in their fatty acid chains, making them solid at room temperature.
• Unsaturated fats: Have one or more double bonds, making them liquid at room temperature.

Diffusion and Osmosis

• Diffusion: Movement of particles from an area of high concentration to low concentration.
• Osmosis: Diffusion of water across a selectively permeable membrane (from high water concentration to low water concentration).
• Hypotonic solution: Lower solute concentration than the cell.
• Hypertonic solution: Higher solute concentration than the cell.
• Isotonic solution: Same solute concentration as the cell.

Cell Organelles

• Nucleus: Control center of the cell, housing DNA.
• Mitochondria: Powerhouse of the cell, generating ATP via cellular respiration.
• Ribosomes: Sites of protein synthesis.
• Endoplasmic reticulum (ER): Involved in protein synthesis and modification (rough ER) and lipid synthesis (smooth ER).
• Golgi apparatus: Modifies, sorts, and packages proteins and lipids.
• Lysosomes: Contain digestive enzymes.
• Peroxisomes: Break down fatty acids and other substances.
• Vacuoles: Storage compartments for water, nutrients, and waste.
• Plasma membrane: Selective barrier controlling flow of substances into and out of the cell.
• Cytoskeleton: Structural support for the cell.
• Centrosomes/Centrioles: Involved in cell division.

Enzymes

• Enzymes: Biological catalysts that speed up chemical reactions by lowering activation energy.
• Enzymes are highly specific for their substrates and can be regulated to control reaction rates.

Compartmentalization

• Cells compartmentalize different biochemical processes into distinct organelles, regulating conditions within each compartment.

Cellular Respiration

• Cellular respiration is the process of converting glucose energy into ATP energy in cells.
• Four main stages occur: glycolysis, pyruvate oxidation, the citric acid cycle, and the electron transport chain. These stages occur in different cellular locations.

Photosynthesis

• Photosynthesis is the process by which plants convert light energy into chemical energy (glucose) using carbon dioxide and water.
• Two main stages: Light-Dependent Reactions and the Calvin Cycle. These occur in different parts of chloroplasts.

DNA Replication

• DNA replication is copying the entire genome to ensure each daughter cell receives a complete set.
• Key players include DNA polymerases, helicases, and primase.
• Occurs in specific locations (origins) and proceeds via two replication forks.
• Multiple steps, like initiation, elongation, and termination.

Gene Regulation

• Gene regulation involves controlling when and how genes are expressed.
• Different mechanisms exist for regulating gene expression (e.g., transcription factors, inhibitors).
• Gene expression is regulated to properly maintain an organism's biological functions.

Vaccines and Herd Immunity

• Vaccines: Biological preparations, which provide immunity against specific diseases, made from weakened or killed forms of a microbe.
• Herd immunity: When a large percentage of a population is immune to a disease, reducing its spread and providing indirect protection to those who lack immunity.

Karyotypes

• Karyotype: A visual representation of an organism's chromosomes. 
• Used to identify numerical and structural abnormalities in chromosomes.

GMOs

• GMO stands for Genetically Modified Organism. 
• GMOs have been genetically altered to produce desirable traits in agriculture or other industries.
• Potential Benefits: Improvements in agriculture, medicine, nutrition, and economics.
• Potential Ethical Concerns: Include health and safety, environmental impact, socio-economic issues, and moral considerations.

Central Dogma

• The Central Dogma outlines the flow of genetic information from DNA to RNA to Protein.
• Transcription: DNA is copied into mRNA.
• Translation: mRNA is used to produce a protein.