Cellular Processes and Cell Biology

• Study notes for College Biology I (BIOL 1610) - Fall 2020, Exam #2 cover chapters 6-10.

Terms

• Mitochondria: Powerhouse of the cell, generates ATP through cellular respiration.
• Nucleoid: Region in prokaryotic cells where DNA is located.
• Nucleus: Membrane-bound organelle in eukaryotic cells containing the genetic material.
• Smooth Endoplasmic Reticulum: Involved in lipid synthesis, detoxification, and calcium storage.
• Rough Endoplasmic Reticulum: Studded with ribosomes, involved in protein synthesis and modification.
• Cytosol: The fluid portion of the cytoplasm, excluding organelles.
• Secretion: The release of substances from a cell.
• Exocytosis: Process by which cells release substances via vesicles fusing with the plasma membrane.
• Endocytosis: Process by which cells take in substances by forming vesicles from the plasma membrane.
• Vacuole: Storage organelle in cells, especially prominent in plant cells.
• Lysosome: Organelle containing enzymes for breaking down cellular waste and debris.
• Cell Wall: Rigid outer layer of plant cells, bacteria, and fungi, providing support and protection.
• Nuclear Envelope: Double membrane surrounding the nucleus.
• Transport Vesicles: Small membrane-bound sacs that transport substances within the cell.
• Golgi Apparatus: Organelle involved in modifying, sorting, and packaging proteins and lipids.
• Chloroplasts: Organelles in plant cells where photosynthesis occurs.
• Peroxisomes: Organelles involved in breaking down fatty acids and detoxifying harmful substances.
• Kinesin: Motor protein that moves along microtubules, transporting cargo within the cell.
• Dynein: Motor protein involved in the movement of cilia and flagella, and also transports cargo along microtubules.
• Cilia: Short, hair-like appendages used for movement or to move substances across the cell surface.
• Flagella: Long, whip-like appendages used for movement.
• Fimbriae: Short, bristle-like appendages on bacteria used for attachment.
• Catabolism: Metabolic processes that break down complex molecules into simpler ones, releasing energy.
• Anabolism: Metabolic processes that build complex molecules from simpler ones, requiring energy.
• Plasmodesmata: Channels through plant cell walls that allow for communication and transport between cells.
• Gap Junctions: Channels between animal cells that allow for direct communication.
• Desmosomes: Cell junctions that provide strong adhesion between animal cells.
• Tight Junctions: Cell junctions that create a tight seal between animal cells, preventing leakage.
• Intermediate Filaments: Cytoskeletal fibers that provide structural support and mechanical strength.
• Actin: Protein that forms microfilaments, involved in cell movement and muscle contraction.
• Microtubules: Hollow tubes made of tubulin, involved in cell division, movement, and transport.
• Cellular Respiration: Process of breaking down glucose to generate ATP, using oxygen.
• Aerobic Respiration: Cellular respiration that requires oxygen.
• Anaerobic Respiration: Cellular respiration that does not require oxygen.
• Fermentation: Anaerobic process of breaking down glucose to generate ATP.
• Glycolysis: Initial stage of cellular respiration and fermentation, breaking down glucose into pyruvate.
• Pyruvate Oxidation: Conversion of pyruvate to acetyl-CoA, linking glycolysis to the citric acid cycle.
• Citric Acid Cycle: Series of reactions that oxidize acetyl-CoA, producing ATP, NADH, and FADH2.
• Electron Transport Chain: Series of protein complexes that transfer electrons, creating a proton gradient to drive ATP synthesis.
• Oxidative Phosphorylation: ATP synthesis powered by the redox reactions of the electron transport chain.
• Chemiosmosis: Movement of ions across a semipermeable membrane, down their electrochemical gradient.
• Photosystem: Protein complex in the thylakoid membrane that absorbs light energy for photosynthesis.
• Chlorophyll: Pigment in chloroplasts that absorbs light energy for photosynthesis.
• Stomata: Pores on plant leaves that allow for gas exchange.
• Thylakoid: Flattened sac-like membrane in chloroplasts where light-dependent reactions occur.
• Light Reaction: Stage of photosynthesis where light energy is converted into chemical energy (ATP and NADPH).
• Calvin Cycle: Stage of photosynthesis where carbon dioxide is fixed and converted into glucose.
• Isotonic: Solution with the same solute concentration as the cell.
• Hypotonic: Solution with a lower solute concentration than the cell.
• Hypertonic: Solution with a higher solute concentration than the cell.
• Passive Transport: Movement of substances across a membrane without the input of energy.
• Active Transport: Movement of substances across a membrane against their concentration gradient, requiring energy.

Guided Questions

Prokaryotes vs. Eukaryotes

• Prokaryotes lack membrane-bound organelles, while eukaryotes possess them.
• Prokaryotes are generally smaller.
• The location of genetic information differs; prokaryotes have it in a nucleoid, while eukaryotes have it in the nucleus.
• Movement strategies/appendages differ between the two cell types.

Animal Cell vs Plant Cell

• Comparing and contrasting features between the two types of cells is important

Cellular Organelles and Functions

• Understanding the various functions of the diverse cell components

Endomembrane System

• Studying how this system functions
• Key endomembrane organelles that are involved
• Knowing function of each organelle and the system as a whole

Free vs Bound Ribosomes

• Comparing and contrasting features between the two types of ribosomes is important

Cytoskeletal Filaments

• Microtubules, actin filaments (microfilaments), and intermediate filaments structure and function should be compared.

Organelle/Structure Alteration

• Being able to predict effects of alteration in a cell

Adaptive Significance of Organelles

• Hypotheses for adaptive significance should be proposed
• This includes weighing the advantages and disadvantages of having membrane-bound structures inside cells.
• Relate the prevalence of organelles in eukaryotes vs. bacteria and archaea.

Membrane Composition and Permeability

• Know the basic composition of the membrane. Selective permeability definition. Determine components that make up the membrane and their functions.

Tonicity

• Define isotonic, hypotonic, and hypertonic solutions.
• Understand water movement in each solution type.
• Be able to predict what happens to the cell in each
• Consider what solutes do you consider when determining tonicity

Passive Transport

• The different types of passive transport should be compared

Active vs. Passive Transport

• Compare active transport and passive transport, also noting what type of transport proteins are involved in active transport.

Free energy

• Determining what it is and what it tells us about a reaction. Also the terms endergonic and exergonic have to be defined

ATP

• Understanding how it performs work in the cell and what types of work it does

Enzymes

• Understanding function of the enzymatic function
• Knowing their structure and binding affinity
• Being able to recognize cofactors and coenzymes
• Knowing how they speed up a chemical reaction

Catabolism vs Anabolism

• Comparing catabolism to anabolism is important to know

Feedback Inhibition

• Understanding how it works and why it is important

Redox Reactions

• Knowing what it is and what happens to electrons for each reaction
• What do protons do in redox reactions should be known

Cellular Respiration and Fermentation

• Knowing where the stages of cellular respiration and fermentation take place in the cell is important
• What does each of these stages require?
• What are each stages end products?
• What is the terminal electron acceptor?
• What is produced in each phase?
• What is the role of FAD and NAD+?
• When do each of the electron carriers become reduced?
• When do each of the electron carriers become oxidized?
• Compare substrate level phosphorylation to oxidative phosphorylation.

Fermentation and Aerobic Cellular Respiration

• Determining what stages they have in common

Mitochondrial Compartment

• Knowing the purpose to translocating protons into the outer mitochondrial compartment is important

Cellular Respiration

• Factors that regulate it should be known

Fermentation Pathways

• Describing fermentation pathways involves understanding the terminal electron acceptor for each pathway and why a terminal electron acceptor is necessary.

Photosynthesis

• Understanding the relation of light reactions to the calvin cycle
• Determining products of each

Photosystems

• Comparing products of photosystem I to photosystem II and classify these light-dependent reactions or calvin cycle reactions

Oxygen

• Knowing how its produced in photosynthesis

Photosynthesis and Cellular Respiration

• Understanding their relationship in depth

ATP

• Determining its role, where it is produced, and the beginning and end products of each.

Photosynthetic Pigments

• Describing them in terms of their absorption spectrum and the purposes of accessory pigments

Antenna Complex and Reaction Center

• Describing the antenna complex and reaction center in photosynthesis must be performed
• Determining what happens when energy is absorbed by a pigment

Photosynthetic Rates

• Describing regulatory mechanisms, including light, sugar content, and CO2 levels

Carbon Fixation

• Comparing different carbon fixation methods is important

Questions about cellular processes and cell biology. Covers cellular respiration, enzyme regulation, photosynthesis, fermentation, and differences between prokaryotic and eukaryotic cells, protein secretion.