Exam study

Page 1: Functional Groups and Biochemical Reactions

  • Functional Groups

    • Hydroxyl Group:

      • Structure: R-OH

      • Common in alcohols (e.g., Ethanol)

    • Carbonyl Group:

      • Variants:

        • Aldehydes: R-C(=O)-H (e.g., Acetaldehyde)

        • Ketones: R-C(=O)-R' (e.g., Acetone)

    • Carboxyl Group:

      • Structure: R-C(=O)-OH

      • Known as carboxylic acids (e.g., Acetic acid)

    • Amino Group:

      • Structure: R-NH2

      • Known as amines (e.g., Methylamine)

  • Biochemical Reactions

    • Condensation Reaction (Dehydration Synthesis):

      • 2 small molecules + energy → large molecule + water

    • Hydrolysis Reaction:

      • Large molecule + water → 2 small molecules + energy

  • Carbohydrates

    • Monosaccharides: Simple sugars with the formula C6H12O6

      • Examples: Glucose (Pyranose form), Fructose (Furanose form), Galactose (Pyranose form)

Page 2: Carbohydrates - Disaccharides and Polysaccharides

  • Disaccharides: Formed by the condensation of two monosaccharides (e.g., sucrose, lactose)

  • Polysaccharides:

    • Starch:

      • Function: Glucose storage in plants (long-term)

    • Glycogen:

      • Function: Glucose storage in animals (short-term energy)

    • Cellulose:

      • Function: Structural support in plants (found in wood, cotton, linen)

    • Chitin:

      • Function: Structural support in organisms (e.g., exoskeleton of crustaceans, fungal cell walls)

      • Also used in contact lenses and surgical thread

Page 3: Lipids - Fatty Acids

  • Fatty Acid Characterization:

    • Length of Carbon Chain:

      • Short chain (less than 8 carbons)

      • Medium chain (8-12 carbons)

      • Long chain (more than 12 carbons)

    • Saturation:

      • Saturated: Only single bonds between carbon atoms

      • Unsaturated: Presence of one or more double bonds (creates kinks)

    • Degrees of Saturation:

      • Saturated fats: solid at room temperature

      • Monounsaturated: one double bond

      • Polyunsaturated: more than two double bonds

    • Hydrogenation: Converts unsaturated fatty acids into saturated by adding hydrogen

    • Fatty Acids:

      • Triglycerides: 1 glycerol + 3 fatty acids

      • Phospholipids: Composed of polar head and nonpolar tails; key component of cell membranes

Page 4: Functions of Phospholipids and Steroids

  • Functions of Phospholipids:

    • Emulsifiers: Help mix oils and water; stabilizes mixtures

    • Cell Membrane Formation: Phospholipid bilayer with hydrophilic heads pointing outwards, allowing flexibility

  • Steroids:

    • Structure: 4 fused carbon rings

    • Functions:

      • Bile acids for fat digestion

      • Synthesize hormones (e.g., testosterone, estrogen)

      • Cholesterol for cell membrane fluidity

      • Used in medicine to reduce inflammation

Page 5: Proteins and Their Structures

  • Proteins: Comprised of polypeptide chains made of amino acids

    • Levels of Structure:

      • Primary Structure: Amino acid sequence; crucial for protein function

      • Secondary Structure: Coiling and folding (Alpha helix and Beta sheet)

      • Tertiary Structure: Overall 3D shape due to interactions between side chains

      • Quaternary Structure: Combination of multiple polypeptide chains

Page 6: Nucleic Acids and Enzymes

  • Nucleotides: Building blocks of nucleic acids (RNA, DNA)

    • Composed of nitrogenous base, pentose sugar (ribose in RNA, deoxyribose in DNA), and phosphate group

  • Enzymes: Catalysts in biological systems; lower activation energy

    • Models of Enzyme Activity:

      • Lock and Key Hypothesis: Every enzyme has a specific substrate

      • Induced Fit Model: Active site changes shape to better fit the substrate

Page 7: Factors Influencing Enzyme Activity

  • Environmental Factors:

    1. Temperature: Each enzyme has an optimal temperature; extreme temperatures can denature enzymes.

    2. pH: Optimal for each enzyme; pH changes can alter function.

    3. Substrate Concentration: Increased concentration can increase enzyme activity until saturation is reached.

  • Cofactors and Coenzymes:

    • Some enzymes require additional molecules for activity; cofactors (inorganic) and coenzymes (organic)

  • Enzyme Regulation:

    • Competitive inhibition, allosteric regulation either inhibiting or activating enzymes.

Page 8: Fluid Mosaic Model and Transport Mechanisms

  • Fluid Mosaic Model: Cell Membrane Structure:

    • Composed of phospholipid bilayer; proteins embedded

  • Factors Affecting Fluidity:

    1. Temperature

    2. Double bonds in fatty acids

    3. Length of fatty acid tails

    4. Presence of cholesterol

  • Transport Mechanisms:

    • Passive Transport: Without energy expenditure; include diffusion and osmosis.

    • Active Transport: Requires energy; moves substances against a gradient.

Page 9: Types of Transport Movement

  • Passive Transport Methods:

    1. Simple Diffusion: High to low concentration until equilibrium.

    2. Osmosis: Diffusion of water across a semipermeable membrane.

    3. Isotonic Solutions: No net movement of water; stable cell volume.

    4. Hypotonic Solutions: Water influx; potential swelling/bursting of cells.

    5. Hypertonic Solutions: Cells lose water; may lead to dehydration.

Page 10: Active Transport Processes

  • Active Transport Methods:

    • Primary Active Transport: Direct use of ATP (e.g., Sodium-Potassium Pump).

    • Secondary Active Transport: Uses the gradient established by primary transport to move other substances.

  • Bulk Transport:

    • Endocytosis: Cell membrane engulfs material (cell drinking/eating).

    • Exocytosis: Vesicles release substances outside the cell.

Page 11: Metabolic Processes

  • Metabolic Energy Concepts:

    • Activation Energy: Energy required to initiate a reaction.

    • Bond Energy: Energy required to break/form bonds.

  • Reactions Types:

    • Exothermic (Catabolic): Energy released.

    • Endothermic (Anabolic): Energy absorbed.

  • Catabolic Pathways: Breakdown of molecules; release energy.

Page 12: Cellular Respiration Processes

  • Cellular Respiration Overview:

    • ADP + Pi → ATP; aim to capture free energy from glucose.

    • Glycolysis overview and net yield: 2 ATPs per glucose.

Page 13: Glycolysis Steps

  • Glycolysis Stages: (Overall yield: 2 ATP, 2 NADH)

    1. Energy Investment Phase: Uses 2 ATP.

    2. Cleavage Phase: Splits glucose into two 3C molecules.

    3. Energy Payoff Phase: Produces 4 ATP and 2 NADH.

Page 14: Pyruvate Oxidation and the Krebs Cycle

  • Pyruvate Oxidation: Converts pyruvate to Acetyl-CoA; produces NADH and CO2.

  • Krebs Cycle Overview:

    • Location: Mitochondrial matrix

    • Products per turn: 3 NADH, 1 FADH2, 2 CO2, 1 ATP (per acetyl-CoA).

Page 15: Electron Transport Chain (ETC)

  • ETC Process:

    • NADH and FADH2 donate electrons to complexes I and II.

    • Electrons are passed through complexes, creating a proton gradient in intermembrane space.

  • Chemiosmosis:

    • Use of H+ gradient to produce ATP.

Page 16: Fermentation Processes

  • Lactate Fermentation: Occurs during anaerobic conditions; converts pyruvate to lactate, allowing glycolysis to continue.

  • Ethanol Fermentation: Converts pyruvate to ethanol; recycling NAD+ for glycolysis.

Page 17: DNA Structure and Replication

  • Modern DNA Model: Double helix structure (sugar-phosphate backbone, bases inside).

  • Replication Mechanism: Semiconservative; DNA strands serve as templates for new strands.

Page 18: DNA Replication Process

  • Process Stages:

    1. Initiation: Helicase unwinds DNA.

    2. Elongation: RNA primers added, DNA polymerase synthesizes new DNA.

    3. Termination: Completes synthesis.

Page 19: Central Dogma of Genetics

  • Processes: DNA → RNA → Protein.

    • Transcription: DNA to mRNA.

    • Translation: mRNA to protein.

Page 20: Mutation Types

  • Single Gene Mutations:

    • Substitutions (silent, missense, nonsense)

    • Frameshifts (insertions, deletions)

  • Chromosomal Mutations: Deletions, duplications, inversions, translocations.

Page 21: Operon and Gene Regulation

  • Operon: Cluster of genes controlled by a single promoter; e.g., Lac operon in E. coli.

  • Regulation Types: Pre-transcriptional (chromatin remodeling), transcriptional (promoter specificity), and post-transcriptional (mRNA modifications).

Page 22: Homeostasis and Feedback Systems

  • Homeostasis Definition: Maintenance of stable internal environment.

  • Feedback Systems: Negative feedback (most common) to maintain balance; positive feedback (less common, e.g., childbirth).

Page 23: Nervous System Components

  • Central Nervous System: Brain and spinal cord; protected by skull and meninges.

  • Peripheral Nervous System: Somatic (voluntary) and autonomic (involuntary).

Page 24: Neurotransmission and Signals

  • Action Potential Mechanism: Resting state, depolarization, repolarization, hyperpolarization, refractory period.

Page 25: Endocrine System Functions

  • Endocrine vs. Exocrine: Hormones directly into bloodstream vs. via ducts.

  • Hormonal Functions: Regulation of body processes; feedback mechanisms ensure equilibrium.