Unit 1 Test Prep: Assignments & Review

• Unit 1 test preparation involves consistent engagement with course material and strategic review techniques.

Assignments

• Complete all assigned work to reinforce understanding.

Cheat Sheet

• Prepare a handwritten cheat sheet (8 ½” x 5 ½”) to consolidate key information.

Notebook

• Complete notebook by checking the table of contents against the whiteboard.

Class Slides

• Review all class slides to reinforce key concepts presented during lectures.

Flashcards

• Create flashcards for all unit vocabulary to aid memorization and quick recall.

Review Activities

• Complete review activities like Blooket to identify areas of weakness.
• Revisit the textbook, videos, class slides, or notes to strengthen understanding.

Scientific Variables

• Understanding scientific variables is crucial for designing and interpreting experiments.
• Independent Variable: Manipulated or changed by the researcher.
• Dependent Variable: Measured to see if it is affected by the independent variable.
• Control Variable: Kept constant to prevent them from influencing the dependent variable.
• Experimental Group: Receives the treatment or manipulation of the independent variable.
• Control Group: Does not receive the treatment and serves as a baseline for comparison.
• Hypothesis: A testable statement or prediction about the relationship between variables.
• Quantitative Data: Numerical data that can be measured and analyzed statistically.
• Qualitative Data: Descriptive data that involves characteristics or qualities that cannot be easily measured.

Graphs

• Data presented visually to identify trends and relationships.

Quantitative Data

• Numerical data that can be measured and analyzed statistically.
• Examples include height, weight, temperature, and reaction rates.

Qualitative Data

• Descriptive data that involves characteristics or qualities that cannot be easily measured.
• Examples include color, texture, smell, and observations.

Graphing Data

• Title: A clear and concise description of what the graph represents.

Axes

• X-axis: Typically represents the independent variable.
• Y-axis: Typically represents the dependent variable.
• Labels: Clearly labeled axes with appropriate units.
• Scale: Appropriate scale to accurately represent the data range.
• Data Points: Accurately plotted data points.
• Trend Line: A line or curve that best fits the data points, showing the relationship between variables.

Experimental Design

• A well-designed experiment is essential for obtaining reliable and valid results.
• Control Group: A group that does not receive the experimental treatment, used as a baseline for comparison.
• Experimental Group: A group that receives the experimental treatment.
• Random Assignment: Participants are randomly assigned to either the control or experimental group to minimize bias.
• Replication: Repeating the experiment multiple times to ensure the results are consistent and reliable.
• Sample Size: A sufficiently large sample size to ensure the results are statistically significant.

Cells

• Cells are the basic units of life.
• Cells: The fundamental structural and functional units of all living organisms.
• Eukaryotic: Cells with a nucleus and other membrane-bound organelles.
• Prokaryotic: Cells without a nucleus or other membrane-bound organelles.
• Cell Organelles: Specialized structures within cells that perform specific functions.

Cell Types

• Understanding the differences between eukaryotic and prokaryotic cells is essential.

Eukaryotic Cells

• Nucleus: Present
• Organelles: Present (e.g., mitochondria, endoplasmic reticulum)
• Size: Larger (10-100 μm)
• Complexity: More complex
• Examples: Animals, Plants, Fungi, Protists

Prokaryotic Cells

• Nucleus: Absent
• Organelles: Absent
• Size: Smaller (0.1-5 μm)
• Complexity: Simpler
• Examples: Bacteria, Archaea

Cell Organelles

• Eukaryotic cells contain various organelles, each with specific functions.
• Nucleus: Contains the cell's DNA and controls cell activities.
• Mitochondria: Produces energy through cellular respiration.
• Endoplasmic Reticulum (ER): Involved in protein and lipid synthesis.
• Golgi Apparatus: Modifies, sorts, and packages proteins and lipids.
• Lysosomes: Contains enzymes for breaking down cellular waste.
• Ribosomes: Synthesizes proteins.

Enzymes

• Enzymes are biological catalysts that speed up chemical reactions in living organisms.
• Enzyme: A protein that acts as a biological catalyst, speeding up chemical reactions.
• Substrate: The molecule upon which an enzyme acts.
• Active Site: The region of an enzyme where the substrate binds and the reaction occurs.
• Denature: The process by which an enzyme loses its shape and function due to changes in temperature, pH, or other factors.

Enzyme Function

• Enzymes facilitate biochemical reactions by lowering the activation energy.

Factors Affecting Enzyme Activity

• Enzyme activity can be influenced by various factors, including temperature and pH.
• Temperature: Enzymes have an optimal temperature range.
  • Too high or too low temperatures can denature the enzyme.
• pH: Enzymes have an optimal pH range.
  • Extreme pH levels can disrupt the enzyme's structure and function.
• Substrate Concentration: Increasing substrate concentration can increase the rate of reaction until the enzyme is saturated.
• Enzyme Concentration: Increasing enzyme concentration can increase the rate of reaction, assuming there is sufficient substrate.
• Inhibitors: Molecules that can bind to enzymes and decrease their activity.

Claim, Evidence, Reasoning (CER)

• CER is a framework for constructing scientific explanations.
• Claim: A statement or conclusion that answers the original question or problem.
• Evidence: Scientific data that supports the claim.
• Reasoning: Justification that connects the evidence to the claim, explaining why the evidence supports the claim using scientific principles.

CER Framework

• The CER framework helps structure scientific arguments.
• Claim: A clear and concise statement that answers the question.
• Evidence: Data or observations that support the claim.
• Reasoning: Explanation of why the evidence supports the claim, using scientific principles and concepts.

Example of CER

• Question: Does increased sunlight affect plant growth?
• Claim: Increased sunlight increases plant growth.
• Evidence: Plants exposed to 12 hours of sunlight per day grew 5 cm taller than plants exposed to 6 hours of sunlight per day over a two-week period.
• Reasoning: Sunlight provides energy for photosynthesis, which is essential for plant growth. More sunlight allows plants to produce more glucose, leading to increased growth.

Key Equations

• Photosynthesis: $6CO_2 + 6H_2O \rightarrow C_6H_{12}O_6 + 6O_2$
• Cellular Respiration: $C_6H_{12}O_6 + 6O_2 \rightarrow 6CO_2 + 6H_2O + ATP$

Review Graphic Organizers and Notes

• Focus on materials like the "biomolecules graphic organizer" and "photosynthesis guided notes."
• These tools provide structured summaries of key concepts.

Assignments

• Ensure completed assignments are understood, including the underlying principles and concepts.

Lab Review

• Review each lab, experimental questions, tested variables, methodology, and results.

Cheat Sheet

• Prepare a single-sided, handwritten cheat sheet to consolidate information and identify areas needing review.

Matter and Biomolecules

• Understanding the fundamental building blocks of life, including matter, monomers, polymers, and the four major biomolecules, is crucial.
• Matter: Anything that has mass and takes up space.
• Law of Conservation of Mass: Mass is neither created nor destroyed in a chemical reaction.
  • The mass of the products = the mass of the reactants.

Monomers and Polymers

• Monomers: Small, repeating units that serve as the building blocks of larger molecules.
• Polymers: Large molecules composed of many monomers bonded together.

Four Biomolecules

• Essential Elements: Key elements (e.g., carbon, hydrogen, oxygen, nitrogen, phosphorus, sulfur) that compose each of the four biomolecules.
• Chemical Tests: Perform and interpret chemical tests for the presence of specific biomolecules and vitamins.
• Mystery molecule lab has practical examples.
• Vitamin C: Tests often involve redox reactions with indicators.
• Reducing Sugars: Benedict's test, where a color change indicates the presence of reducing sugars.
• Starches: Iodine test, where a blue-black color indicates the presence of starch.
• Lipids: Sudan III or IV dye test, where the dye stains lipids, indicating their presence.
• Proteins: Biuret test, where a violet color indicates the presence of peptide bonds.

Energy

• Energy is the capacity to do work.
• Definition of Energy: Energy is the ability to do work or cause change.

Examples of Energy

• Kinetic Energy: The energy of motion (e.g., a moving car).
• Potential Energy: Stored energy (e.g., a battery).
• Thermal Energy: Heat energy (e.g., a stove).

ATP

• ATP (Adenosine Triphosphate): The primary energy currency of the cell.
• A nucleotide that stores and transports chemical energy within cells for metabolism.
• ATP Usage: Cells use ATP for various energy-requiring processes, including:
  • Muscle contraction
  • Active transport of molecules across membranes
  • Synthesis of new molecules
• ADP to ATP Analogy: Conversion of ADP (adenosine diphosphate) to ATP is analogous to recharging a battery.
• Adding a phosphate group to ADP stores energy.
• Obtaining Energy from Glucose: Organisms obtain energy from glucose through cellular respiration.
• Process breaks down glucose to release energy, used to generate ATP.

Cellular Respiration

• Cellular respiration is the process by which organisms convert glucose into usable energy in the form of ATP.
• Location: Primarily takes place in the mitochondria of eukaryotic cells.
• Inputs: Glucose ($C_6H_{12}O_6$) and oxygen ($O_2$).
• Outputs: Carbon dioxide ($CO_2$), water ($H_2O$), and ATP.
• Equation: $C_6H_{12}O_6 + 6O_2 \rightarrow 6CO_2 + 6H_2O + ATP$
• Source of Requirements:
  • Glucose: From food intake.
  • Oxygen: From breathing.

Stages of Cellular Respiration

• Glycolysis: Occurs in the cytoplasm.
• Krebs Cycle (Citric Acid Cycle): Occurs in the mitochondrial matrix.
• Electron Transport Chain (ETC): Occurs in the inner mitochondrial membrane.
• Anaerobic Stage: Glycolysis does not require oxygen and takes place in the cytoplasm.
• Aerobic vs. Anaerobic Respiration:
  • Aerobic Respiration: Requires oxygen to produce ATP.
  • Anaerobic Respiration: Does not require oxygen and produces less ATP.

Types of Anaerobic Respiration (Fermentation)

Lactic Acid Fermentation

• Inputs: Glucose, NADH
• Outputs: Lactic acid, $NAD^+$

Alcoholic Fermentation

• Inputs: Glucose, NADH
• Outputs: Ethanol, Carbon dioxide, $NAD^+$
• ATP Production: Aerobic respiration produces significantly more ATP than anaerobic respiration.
• Switch to Anaerobic Respiration: During exercise, your body switches to anaerobic respiration when oxygen supply cannot meet the energy demands of your muscles.
• Necessity of Anaerobic Respiration: During intense exercise, anaerobic respiration becomes necessary because it allows your muscles to continue producing ATP even when oxygen is limited, although less efficiently.

Photosynthesis

• Photosynthesis is the process by which autotrophs convert light energy into chemical energy in the form of glucose.
• Heterotrophs vs. Autotrophs:
  • Heterotrophs: Organisms that obtain energy by consuming other organisms.
  • Autotrophs: Organisms that produce their own food through photosynthesis or chemosynthesis.
• Source of Tree Mass: Trees get their mass primarily from carbon dioxide ($CO_2$) absorbed from the air during photosynthesis.
• Inputs and Outputs:
  • Inputs: Carbon dioxide ($CO_2$) and water ($H_2O$).
  • Outputs: Glucose ($C_6H_{12}O_6$) and oxygen ($O_2$).
• Equation: $6CO_2 + 6H_2O + \text{Light Energy} \rightarrow C_6H_{12}O_6 + 6O_2$
• $CO_2$ and Water Intake: Plants take in carbon dioxide through stomata (small pores) on their leaves and water through their roots.
• Site of Photosynthesis: The site of photosynthesis in plant cells is the chloroplast.
• Role of Chlorophyll: Chlorophyll is a pigment that absorbs light energy used to drive photosynthesis.

Reactions

• Light-Dependent Reactions: Occur in the thylakoid membranes of the chloroplast.
• Light-Independent Reactions (Calvin Cycle): Occur in the stroma of the chloroplast.

Light-Dependent Reactions

• Used: Water ($H_2O$) and light energy.
• Made: ATP, NADPH, and oxygen ($O_2$).

Light-Independent Reactions (Calvin Cycle)

• Used: Carbon dioxide ($CO_2$), ATP, and NADPH.
• Made: Glucose ($C_6H_{12}O_6$).

Photosynthesis Summary

• Photosynthesis is a process where plants use light energy to convert carbon dioxide and water into glucose and oxygen.
• The light-dependent reactions capture light energy and produce ATP and NADPH.
• The Calvin cycle converts carbon dioxide into glucose.
• Ecosystem Essentiality: Photosynthesis is essential as it provides the primary source of energy and organic compounds.
• It also produces oxygen, which is vital for the respiration of many organisms.
• Photosynthesis Lab: Rate of photosynthesis calculated using $CO_2$ concentrations.
• A decrease in $CO_2$ concentration over time indicates a higher rate of photosynthesis.
• Rate can be quantified by measuring the change in $CO_2$ concentration per unit time.
• Rate of Photosynthesis $ = \frac{\Delta [CO_2]}{\Delta t}$