Biol 112 Exam Study Guide PDF
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This document provides a study guide for a biology course, focusing on topics like cell structure and function, macromolecules and other biological processes. This study guide is for Biol 112.
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## Biol 112 Exam Study Guide ## WEEK 1: The Cell # **1.3 The Cell** - **Plasma Membrane:** Separates living material inside the cell from the external environment, controlling material movement in/out of the cell. - **Prokaryotes vs. Eukaryotes:** - **Prokaryotes:** No...
## Biol 112 Exam Study Guide ## WEEK 1: The Cell # **1.3 The Cell** - **Plasma Membrane:** Separates living material inside the cell from the external environment, controlling material movement in/out of the cell. - **Prokaryotes vs. Eukaryotes:** - **Prokaryotes:** No nucleus, single-celled, small size, rapid reproduction. - **Eukaryotes:** Nucleus present, multicellular or unicellular, specialized cells. - **Three Domains:** Bacteria, Archaea (Prokaryotes), Eukarya (Eukaryotes). - **Central Dogma:** DNA → RNA (transcription) → Protein (translation). - **DNA Replication:** Highly precise; errors lead to mutations and diversity. * *3.1 Cell Theory** - **Principles:** 1. All organisms are made up of cells. 2. The cell is the fundamental unit of life. 3. Cells arise from preexisting cells. --- ## WEEK 2: Macromolecules # **Types of Macromolecules** 1. **Proteins:** Structural support, enzymes. 2. **Nucleic Acids:** Genetic information (DNA, RNA). 3. **Carbohydrates:** Energy source and cell wall material. 4. **Lipids:** Cell membranes, energy storage, signaling molecules. * *Amino Acids and Proteins** - **Structure:** Central carbon atom bound to amino group, carboxyl group, hydrogen atom, and R group. - **Protein Folding:** - **Primary:** Amino acid sequence. - **Secondary:** α-helices and β-sheets from H-bonds. - **Tertiary:** 3D shape from R group interactions. - **Quaternary:** Assembly of multiple polypeptides. * *Nucleic Acids** - **DNA:** Double-stranded, deoxyribose sugar, bases A, T, G, C. - **RNA:** Single-stranded, ribose sugar, bases A, U, G, C. - Base Pairing: A-T (or A-U in RNA), G-C. --- ## WEEK 3: Membranes and Transport # **Structure of Cell Membranes** - **Components:** Phospholipids (bilayer), proteins, carbohydrates. - **Phospholipids:** Amphipathic with hydrophilic heads and hydrophobic tails. - **Cholesterol:** Maintains fluidity in membranes. * *Membrane Transport** 1. **Passive Transport:** Diffusion and facilitated diffusion down a concentration gradient. 2. **Active Transport:** Uses ATP to move substances against a gradient. 3. **Osmosis:** Water movement from low solute concentration to high solute concentration. --- ## WEEK 4: Transcription and Translation # **Transcription** - Converts DNA to RNA using RNA polymerase. - Stages: Initiation (promoter), Elongation (nucleotide addition), Termination (stop sequence). - Eukaryotic RNA undergoes processing: - **5' Cap and Poly(A) Tail:** Stability and recognition. - **Splicing:** Removes introns, joins exons. * *Translation** - Converts mRNA into a polypeptide chain. - **Steps:** 1. **Initiation:** Ribosome assembles at start codon (AUG). 2. **Elongation:** tRNA adds amino acids. 3. **Termination:** Stop codon ends translation. - **Ribosome Sites:** A (aminoacyl), P (peptidyl), E (exit). --- ## WEEK 5: DNA Structure and Replication # **DNA Structure** - Double helix, antiparallel strands. - Backbone: Sugar-phosphate; bases inside. - **Replication:** Semiconservative process: - **Leading Strand:** Continuous synthesis. - **Lagging Strand:** Synthesized in Okazaki fragments. - Enzymes: - **Helicase:** Unwinds DNA. - **DNA Polymerase:** Adds nucleotides. - **Ligase:** Joins fragments. --- ## WEEK 6: Gene Regulation # **Prokaryotic Regulation** - **Lac Operon:** - Inducible system for lactose metabolism. - Repressor binds operator; lactose presence removes repressor. * *Eukaryotic Regulation** - Transcription factors and enhancers regulate gene expression. - **Epigenetics:** Modifications like methylation influence gene activity without altering DNA sequence. --- ## Key Diagrams to Review # - DNA replication fork. - Central dogma flow (DNA → RNA → Protein). - Lac operon structure. - Membrane structure and transport mechanisms. --- ## Exam Tips # - Focus on processes and their steps (e.g., transcription, replication). - Understand key differences between prokaryotic and eukaryotic cells. - Practice drawing and labeling structures (DNA, operons, membranes). - Study enzyme roles and function in replication and transcription. --- ### Additional Topics from New Notes * *DNA Replication and Cell Division** - **Replication Fork:** Point where parental strands separate. Leading strand is synthesized continuously, lagging strand in Okazaki fragments. - **Key Enzymes:** - **Helicase:** Unwinds strands. - **Topoisomerase:** Relieves strain during unwinding. - **RNA Primase:** Adds RNA primer. - **DNA Polymerase:** Synthesizes new strands and proofreads. - **Ligase:** Joins Okazaki fragments. * *Metabolism** - **Types of Organisms by Energy Source:** - **Phototrophs:** Use sunlight for energy. - **Chemotrophs:** Use chemical compounds. - **Autotrophs:** Produce their own food. - **Heterotrophs:** Consume other organisms. - **Reactions:** - **Catabolism:** Breaks molecules down, releases energy. - **Anabolism:** Builds molecules, requires energy. * *Cellular Respiration** 1. **Glycolysis:** Glucose → Pyruvate + ATP. 2. **Pyruvate Oxidation:** Pyruvate → Acetyl-CoA + CO2. 3. **Citric Acid Cycle:** Acetyl-CoA → ATP + Electron carriers. 4. **Oxidative Phosphorylation:** Electron carriers drive ATP synthesis. * *Photosynthesis** - **Light Reactions:** Sunlight → ATP + NADPH. - **Calvin Cycle:** Uses ATP + NADPH to fix CO2 into carbohydrates. - Occurs in chloroplasts: Light reactions in thylakoid, Calvin cycle in stroma. * *Enzymes** - Lower activation energy to speed up reactions. - **Active Site:** Substrate binds specifically, forming an enzyme-substrate complex. - **Cofactors:** Non-protein helpers for enzymatic activity. * *Energy in Biological Systems** - **ATP:** Main energy currency; produced by substrate-level and oxidative phosphorylation. - **Redox Reactions:** Oxidation (loss of electrons) and reduction (gain of electrons) occur together in metabolic pathways. * *Directionality of Transcription and Translation** - RNA polymerase moves on template strand 3′ to 5′. - mRNA synthesized 5′ to 3′. - Promoter on 3′ side; first RNA pol on 5′ side. - N-terminus corresponds to 5′ end; C-terminus to 3′ end. * *DNA Mutations** - **Silent:** No effect on amino acid sequence. - **Missense:** Substitutes one amino acid for another. - **Nonsense:** Creates a premature stop codon. - **Frameshift:** Insertion or deletion shifts the reading frame. * *Gene Regulation** - Operon structure: promoter, operator, and genes. - **Lac Operon:** - Lactose absent: Basal transcription. - Lactose present: High transcription levels. - Positive regulation: Enhances transcription with activators. - Negative regulation: Decreases transcription with repressors. * *Polymerase Chain Reaction (PCR)** 1. Denaturation (high temperature). 2. Annealing (lower temperature). 3. Extension (medium temperature). - Components: DNA template, primers, DNA polymerase, dNTPs. - Produces exponential amplification of target DNA sequences. * *Fermentation** - Restores NAD+ for glycolysis in absence of electron transport chain. - Produces less ATP than aerobic respiration. * *Cellular Respiration Overview** - **Inputs and Outputs:** - Glycolysis: Glucose → Pyruvate + ATP + NADH. - Citric Acid Cycle: Acetyl-CoA → CO2 + ATP + NADH/FADH2. - Oxidative Phosphorylation: O2 + NADH/FADH2 → H2O + ATP. - **Steps:** Electron transport chain creates a proton gradient, driving ATP synthesis via ATP synthase. * *Photosynthesis Overview** - **Inputs and Outputs:** - Light Reactions: H2O + light → O2 + ATP + NADPH. - Calvin Cycle: CO2 + ATP + NADPH → G3P. - Occurs in chloroplasts, utilizing light energy to produce carbohydrates.
