Untitled Flashcards Set

- Theory: A well-supported explanation of something based on a lot of evidence and experiments.  

- Independent variable: The factor you change or manipulate in an experiment. 

- Dependent variable: The factor you measure or observe, which depends on the independent variable.  

- Standardized variable: Things that stay the same in all parts of the experiment to keep it fair.  

- Positive control: A group or condition expected to give a positive result, making sure the experiment works.  

- Negative control: A group or condition that should show no effect, used to see what happens without any treatment.  

- Analysis: The process of looking at the experiment data to understand what happened.  

- Conclusion: A decision made after reviewing the data to see if the hypothesis was correct or not.  

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Questions and Answers  

1. Outline the main steps of the scientific method.  

   - Ask a question: Figure out what you want to learn about.  

   - Do background research: Find out what’s already known about the topic.  

   - Form a hypothesis: Make a guess about what you think will happen.  

   - Design an experiment: Plan how you’ll test your hypothesis.  

   - Conduct the experiment: Do the experiment and collect the results.  

   - Analyze the data: Look at the results and see if they support your hypothesis.  

   - Draw a conclusion: Decide if your hypothesis was right or wrong.  

   - Share results: Tell others about what you found out.  

Proton: A positively charged particle found in the nucleus of an atom.

- Neutron: A particle with no charge (neutral) found in the nucleus of an atom.

- Electron: A negatively charged particle that orbits the nucleus of an atom.

- Atom: The smallest unit of an element, made of protons, neutrons, and electrons.

- Element: A substance made of only one type of atom.

- Ion: An atom or molecule that has gained or lost electrons, resulting in a charge.

- Isotope: Atoms of the same element with the same number of protons but different numbers of neutrons.

- Electron orbital/shell: The regions around an atom's nucleus where electrons are likely to be found.

- Bond: A connection between atoms that holds them together in molecules.

  - Covalent bond: A bond where two atoms share electrons.

  - Ionic bond: A bond where one atom gives an electron to another, creating positive and negative ions that attract each other.

  - Hydrogen bond: A weak bond between a hydrogen atom in one molecule and an electronegative atom (like oxygen or nitrogen) in another molecule.

- Solvent/solute:

  - Solvent: A substance that dissolves another substance (e.g., water).

  - Solute: The substance that is dissolved (e.g., salt in water).

- pH: A measure of how acidic or basic a solution is, based on hydrogen ion concentration.

- Acid/base vs. acidic/basic: 

  - Acid: A substance that increases hydrogen ions (H⁺) in a solution.

  - Base: A substance that decreases hydrogen ions (H⁺) in a solution.

  - Acidic: A solution with a low pH (more H⁺).

  - Basic: A solution with a high pH (fewer H⁺).

- Buffer: A substance that helps maintain a stable pH in a solution by neutralizing acids or bases.

- Kinetic energy: The energy an object has because it is in motion. Atoms and molecules have kinetic energy due to their constant movement.

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Study Guide Questions and Answers

1. Be able to explain what the different numbers mean in one tile of the periodic table.  

   - The atomic number is the number of protons in the nucleus of an atom and defines the element (e.g., carbon has 6 protons).

   - The atomic mass (or weight) is the total number of protons and neutrons in an atom.

2. Explain why the number of electrons has such a strong effect on an element's stability/reactivity.  

   The number of electrons determines how an atom interacts with others. Atoms are more stable when their outermost electron shell is full. If it isn’t full, they will react with other atoms to fill their shell, making them more reactive.

3. What is an isotope?  

   An isotope is an atom of the same element (same number of protons) but with a different number of neutrons. This can affect the atom’s mass and its stability.

4. Compare and contrast the following types of bonds: covalent, ionic, hydrogen.  

   - Covalent bond: Atoms share electrons (e.g., in water, H₂O).

   - Ionic bond: One atom gives an electron to another, creating ions that attract each other (e.g., salt, NaCl).

   - Hydrogen bond: A weak bond between a hydrogen atom and an electronegative atom (e.g., the bond between water molecules).

5. Contrast the bonds that hold together H and O atoms in a water molecule, and those that hold together H2O molecules in water and ice.  

   - The H-O bond within a water molecule is a covalent bond, where electrons are shared.

   - The bonds between water molecules are hydrogen bonds, which are weaker than covalent bonds but help water molecules stick together. These bonds are stronger in ice than in liquid water, making ice less dense than liquid water.

6. Why is it difficult to heat up (or cool down) water?  

   Water has a high specific heat capacity, meaning it requires a lot of energy to change its temperature. This is because water molecules are held together by hydrogen bonds, which absorb a lot of energy before the temperature changes.

7. Why is water such a good solvent? Are there any substances water cannot dissolve? Why or why not?  

   Water is a good solvent because it is polar, meaning it has a partial positive charge on the hydrogen atoms and a partial negative charge on the oxygen atom. This allows it to dissolve many substances, especially those that are also polar or ionic. Water cannot dissolve non-polar substances, like oil, because they don’t interact well with water molecules.

8. What is surface tension? Give some biological examples of how surface tension in water affects organisms.  

   Surface tension is the force that makes the surface of water act like a stretched elastic membrane. It helps small insects (like water striders) walk on water and allows the formation of water droplets.

9. Explain the relationship between the kinetic energy of atoms/molecules and temperature.  

   The kinetic energy of atoms and molecules increases with temperature. As temperature rises, the molecules move faster and collide more, causing an increase in energy.

10. Relate pH to hydrogen ion concentration.  

   pH measures the concentration of hydrogen ions (H⁺) in a solution. A low pH (acidic) means there are more hydrogen ions, and a high pH (basic) means there are fewer hydrogen ions.

11. What specifically does lowered pH do to proteins?  

   Lowered pH (more acidic conditions) can cause proteins to denature, meaning they lose their shape and cannot function properly. This can be harmful to cells and enzymes.

12. What are buffers? What do they do? Why are they important?  

   Buffers are substances that help maintain a stable pH in a solution by either absorbing excess hydrogen ions or releasing them when needed. They are important because they help keep the body’s pH at a level that supports proper function.

13. How does CO2 contribute to buffering in your body? In the ocean?  

   - In the body, CO₂ reacts with water to form carbonic acid, which helps maintain the pH of the blood.

   - In the ocean, excess CO₂ can lower the pH, making the water more acidic, which can harm marine life, especially organisms with calcium-based shells or skeletons.

14. What are the consequences of a build-up of CO2 on the pH of any aquatic system?  

   A build-up of CO₂ causes more carbonic acid to form, which lowers the pH (makes the water more acidic). This can negatively affect marine life, particularly organisms like corals and shellfish that rely on calcium to build their shells and skeletons.

### Vocabulary:

1. Phospholipid:  

   - A type of fat that forms the basic structure of the cell membrane. It has a "head" that likes water (hydrophilic) and "tails" that dislike water (hydrophobic).

2. Phospholipid Bilayer:  

   - A two-layer arrangement of phospholipids that forms the cell membrane. The hydrophilic heads face outward toward water, while the hydrophobic tails face inward away from water.

3. Semipermeable:  

   - A property of the cell membrane where it allows some substances to pass through, but blocks others.

4. Exocytosis:  

   - The process by which cells release substances (like waste or proteins) to the outside by forming a vesicle that fuses with the cell membrane.

5. Endocytosis:  

   - The process by which cells take in substances from the outside by engulfing them into a vesicle.

6. Tonicity:  

   - Describes the concentration of solutes in a solution compared to another solution. 

     - Isotonic: Equal solute concentration inside and outside the cell.

     - Hypotonic: Lower solute concentration outside the cell, so water enters the cell.

     - Hypertonic: Higher solute concentration outside the cell, so water leaves the cell.

7. Osmosis:  

   - The movement of water across a semipermeable membrane from an area of low solute concentration to an area of high solute concentration.

8. Diffusion:  

   - The movement of molecules (like gases or small particles) from an area of high concentration to an area of low concentration.

9. Extracellular Fluid:  

   - The fluid outside the cells, including blood plasma and interstitial fluid.

10. Intracellular Fluid:  

   - The fluid inside the cells, also called cytoplasm.

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### Study Guide Questions:

1. Describe the structure of the cell membrane.  

   The cell membrane is made up of a phospholipid bilayer, with phospholipids arranged so that their hydrophilic "heads" face the outside and inside of the cell (toward water), while their hydrophobic "tails" face each other, away from water. This creates a semi-permeable barrier. The membrane also contains proteins, cholesterol, and other molecules.

2. How does the structure of the cell membrane affect its function? What IS its function?  

   The structure of the cell membrane allows it to be semi-permeable, meaning it controls what enters and leaves the cell. The phospholipid bilayer is flexible and fluid, allowing the membrane to adjust and interact with different substances. The function of the membrane is to protect the cell, communicate with other cells, and regulate the flow of materials into and out of the cell.

3. Why is the cell membrane said to be a fluid mosaic?  

   The cell membrane is called a fluid mosaic because it is flexible (fluid) and made up of many different components (mosaic), such as phospholipids, proteins, and cholesterol, all moving around within the layer.

4. What roles do proteins play in the cell membrane?  

   Proteins in the cell membrane have several roles:

   - Transport proteins help move substances across the membrane.

   - Receptor proteins receive signals from outside the cell.

   - Enzymatic proteins catalyze chemical reactions.

   - Structural proteins help maintain the cell’s shape.

5. What roles does cholesterol play in the cell membrane?  

   Cholesterol helps stabilize the cell membrane by preventing it from becoming too rigid or too fluid. It helps the membrane maintain its flexibility across different temperatures.

6. How do substances get into and out of the cell?  

   Substances move into and out of the cell through different mechanisms:

   - Passive transport (no energy required) includes diffusion and osmosis.

   - Active transport (requires energy) uses transport proteins to move substances against a concentration gradient.

7. Compare and contrast active and passive transport.  

   - Passive Transport: Moves substances from high to low concentration without using energy (e.g., diffusion, osmosis).

   - Active Transport: Moves substances from low to high concentration, requiring energy (ATP) (e.g., sodium-potassium pump).

8. Compare and contrast simple diffusion and facilitated diffusion.  

   - Simple Diffusion: Small molecules, like oxygen or carbon dioxide, move directly through the membrane from high to low concentration.

   - Facilitated Diffusion: Larger or charged molecules move through the membrane with the help of a protein channel (still from high to low concentration, but with help).

9. Compare and contrast endocytosis and exocytosis.  

   - Endocytosis: The cell takes in substances by engulfing them into a vesicle (e.g., when cells take in nutrients).

   - Exocytosis: The cell expels substances by vesicles fusing with the membrane (e.g., releasing waste or proteins outside the cell).

10. Define osmosis.  

    Osmosis is the movement of water across a semipermeable membrane from an area of low solute concentration to an area of high solute concentration.

11. Describe the concept of tonicity.  

    - Isotonic: Same solute concentration inside and outside the cell (no water movement).

    - Hypotonic: Lower solute concentration outside the cell, water moves into the cell (cell may swell).

    - Hypertonic: Higher solute concentration outside the cell, water moves out of the cell (cell may shrink).

12. Given a specific example, be able to determine if and in which direction water and/or solutes would flow between two compartments divided by a semipermeable membrane.  

    - Example: If you have a hypotonic solution on the outside of the cell and higher solute concentration inside the cell, water will flow into the cell to balance the concentrations.

    - If you have a hypertonic solution outside the cell, water will flow out of the cell to balance the solute concentration.

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These answers explain the key functions and characteristics of the cell membrane and transport processes in simple terms!

### Vocabulary Definitions:

1. Mitochondrion:  

   - Outer membrane: The outer boundary of the mitochondrion.  

   - Inner membrane: The membrane inside the mitochondrion, where the electron transport chain (ETC) and ATP synthase are located.  

   - Intermembrane space: The space between the outer and inner membranes of the mitochondrion.  

   - Matrix: The fluid-filled space inside the inner membrane where the Krebs cycle takes place.

2. Glycolysis:  

   - The breakdown of glucose (6-carbon molecule) into two molecules of pyruvate (3-carbon molecules), producing small amounts of ATP and NADH in the cytoplasm.

3. Krebs/Citric Acid Cycle:  

   - A cycle of reactions in the mitochondria that processes acetyl-CoA (derived from pyruvate) to produce NADH, FADH2, ATP, and carbon dioxide (CO2).

4. Oxidative Phosphorylation:  

   - The final stage of cellular respiration, involving the electron transport chain (ETC) and chemiosmosis, where ATP is produced using energy from electrons carried by NADH and FADH2. Oxygen acts as the final electron acceptor.

5. NADH, FADH2:  

   - NADH and FADH2 are electron carriers that transport electrons to the electron transport chain during cellular respiration.

6. Glucose/Pyruvate/Acetyl-CoA:  

   - Glucose: A simple sugar that is the starting point for cellular respiration.  

   - Pyruvate: The product of glycolysis, a 3-carbon molecule that is further processed into acetyl-CoA.  

   - Acetyl-CoA: The molecule that enters the Krebs cycle after pyruvate is converted.

7. ATP Synthase:  

   - An enzyme that synthesizes ATP from ADP and inorganic phosphate (Pi) during oxidative phosphorylation, using the energy from a proton gradient (H+).

8. Fermentation:  

   - An anaerobic process that allows cells to generate ATP without oxygen, typically producing lactic acid (in animals) or ethanol and CO2 (in yeast).

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### Study Guide Questions:

1. What is the chemical equation that describes cellular respiration?  

   The general equation for cellular respiration is:  

   \[ \text{Glucose (C}_6\text{H}_12\text{O}_6\text{) + 6O}_2 \rightarrow 6CO_2 + 6H_2O + \text{ATP} \]

2. What are the reactants and what are the products of cellular respiration overall?  

   - Reactants: Glucose (C6H12O6) and oxygen (O2).  

   - Products: Carbon dioxide (CO2), water (H2O), and ATP (energy).

3. Where does each stage of cellular respiration take place?

   - Glycolysis: In the cytoplasm.  

   - Acetyl-CoA formation: In the mitochondrial matrix.  

   - Krebs cycle: In the mitochondrial matrix.  

   - Oxidative phosphorylation: Across the inner mitochondrial membrane (electron transport chain and ATP synthase).

4. Name and describe the function of the electron carriers in cellular respiration.

   - NADH: Carries electrons from glycolysis and the Krebs cycle to the electron transport chain.  

   - FADH2: Carries electrons from the Krebs cycle to the electron transport chain. These electron carriers are crucial for oxidative phosphorylation and ATP production.

5. Be able to do "energy accounting" for each stage of cellular respiration: account for the electron carriers and ATP molecules.

   - Glycolysis:  

     - Produces 2 ATP (net) and 2 NADH.  

     - The 2 NADH will carry electrons to the electron transport chain.  

   - Acetyl-CoA formation:  

     - Produces 2 NADH (for each glucose molecule).  

   - Krebs cycle:  

     - Produces 2 ATP, 6 NADH, and 2 FADH2 (per glucose).  

     - These electron carriers will go to the electron transport chain.  

   - Oxidative phosphorylation:  

     - ATP is generated via chemiosmosis (about 34 ATP).  

     - NADH and FADH2 donate electrons to the electron transport chain, where energy is used to pump protons, and ATP is synthesized.

6. Explain the functional role of oxygen in cellular respiration.  

   - Oxygen acts as the final electron acceptor in the electron transport chain. It combines with electrons and protons to form water (H2O), which is a byproduct of cellular respiration. Without oxygen, the electron transport chain would stop, halting ATP production.

7. Glucose is used in cellular respiration. Where does it come from?  

   - Glucose comes from the food we eat, primarily carbohydrates like starch and sugars. It is absorbed into the bloodstream during digestion and transported to cells for energy production.

8. Oxygen is used in cellular respiration. Where does it come from? What is the oxygen used for?  

   - Oxygen comes from the air we breathe. It is used at the end of the electron transport chain to accept electrons and protons, forming water (H2O).

9. Water is produced in cellular respiration. In which step of the process is it created?  

   - Water is produced during oxidative phosphorylation when oxygen acts as the final electron acceptor in the electron transport chain and combines with electrons and protons.

10. Carbon dioxide is produced in cellular respiration. In which step of the process is it created?  

    - Carbon dioxide is produced during the Krebs cycle (also called the citric acid cycle). Each turn of the cycle generates 2 molecules of CO2 as a waste product.

11. What role do hydrogen ions play in the process?  

    - Hydrogen ions (H+) are pumped across the inner mitochondrial membrane during oxidative phosphorylation. This creates a proton gradient, which is used by ATP synthase to produce ATP.

12. Is feeding glucose into glycolysis the only way to reap the benefits of oxidative phosphorylation?  

    - No, glucose is not the only molecule that can feed into glycolysis. Fatty acids and proteins can also be broken down into molecules (like acetyl-CoA) that enter the Krebs cycle, which then allows oxidative phosphorylation to occur.

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These answers should help clarify the processes involved in cellular respiration and the role of each molecule in the production of energy!

### Vocabulary Definitions:

1. Stomata:  

   - Small pores on the surface of leaves that allow gas exchange (carbon dioxide in, oxygen out) and water vapor to escape.

2. Stroma:  

   - The fluid-filled space inside the chloroplast, surrounding the thylakoids. The Calvin cycle occurs in the stroma.

3. Grana/Granum:  

   - Stacks of thylakoid membranes in the chloroplast. A granum is a stack, while grana is the plural.

4. Thylakoid:  

   - Membrane-bound structures within the chloroplast where the light-dependent reactions of photosynthesis occur.

5. Thylakoid space:  

   - The inner space inside the thylakoid membrane, where protons (H+) accumulate during the light reactions.

6. Inner/Outer membrane:  

   - Outer membrane: The outermost membrane of the chloroplast.  

   - Inner membrane: The inner membrane that surrounds the stroma and contains the thylakoids.

7. Pigment molecules:  

   - Molecules that absorb light energy for photosynthesis. The primary pigment in plants is chlorophyll.

8. Chlorophyll:  

   - The green pigment in plants responsible for capturing light energy during photosynthesis.

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### Study Guide Questions:

1. Write out the equation for photosynthesis.

   - The overall chemical equation for photosynthesis is:

   \[

   6CO_2 + 6H_2O + \text{light energy} \rightarrow C_6H_{12}O_6 + 6O_2

   \]

   This shows that carbon dioxide and water, using light energy, are converted into glucose and oxygen.

2. Describe the structure of a chloroplast.

   - The chloroplast consists of:

     - Outer membrane: Surrounds the entire chloroplast.

     - Inner membrane: Surrounds the stroma and contains the thylakoids.

     - Stroma: Fluid-filled space where the Calvin cycle occurs.

     - Grana/Granum: Stacks of thylakoids, where light-dependent reactions take place.

     - Thylakoids: Membrane-bound structures inside the grana that house pigment molecules and are involved in the light reactions.

3. Where do the different stages of photosynthesis take place?

   - Light-dependent reactions: Occur in the thylakoid membranes.

   - Calvin cycle (light-independent reactions): Occurs in the stroma of the chloroplast.

4. Describe each stage and their steps in the process of photosynthesis. What are the general reactants and products of each stage?

   - Light-dependent reactions (occur in the thylakoid membranes):

     - Reactants: Water (H2O) and light energy.

     - Products: ATP, NADPH, and oxygen (O2).

     - In these reactions, light energy is absorbed by chlorophyll, and water is split to release oxygen. Energy is stored in ATP and NADPH, which are used in the next stage.

   - Calvin cycle (occur in the stroma):

     - Reactants: Carbon dioxide (CO2), ATP, and NADPH.

     - Products: Glucose (C6H12O6).

     - This cycle uses ATP and NADPH from the light-dependent reactions to convert carbon dioxide into glucose, which the plant uses for energy.

5. Explain the different roles of photosystem I and photosystem II, and the difference between light and dark reactions.

   - Photosystem II:

     - Located in the thylakoid membrane, Photosystem II absorbs light, which excites electrons. These electrons are transferred to the electron transport chain (ETC), leading to the formation of ATP and NADPH.

   - Photosystem I:

     - Also in the thylakoid membrane, Photosystem I absorbs light and re-excites the electrons from Photosystem II. These electrons help produce NADPH.

   - Light reactions (light-dependent reactions) require light and take place in the thylakoid membrane. They convert light energy into chemical energy (ATP and NADPH) and release oxygen.

   - Dark reactions (Calvin cycle or light-independent reactions) do not require light. They occur in the stroma and use ATP and NADPH from the light reactions to convert CO2 into glucose.

6. How is the Calvin cycle connected to events in Photosystems II and I?

   - The Calvin cycle uses the ATP and NADPH produced by Photosystem II and Photosystem I during the light-dependent reactions. These molecules provide the energy and electrons needed to convert CO2 into glucose in the stroma.

7. Where does the sugar come from when a plant undergoes cellular respiration?

   - The sugar used in cellular respiration comes from glucose, which is produced during photosynthesis in the chloroplasts.

8. Where does the oxygen come from when a plant undergoes cellular respiration? What is the oxygen used for?

   - The oxygen released during photosynthesis comes from the splitting of water molecules in the light-dependent reactions. Oxygen is then released as a byproduct into the air. In cellular respiration, oxygen is used as the final electron acceptor in the electron transport chain to produce water.

9. What is the adaptive significance of C4 and CAM variations on "typical" C3 photosynthesis?

   - C3 photosynthesis: The typical photosynthetic process in most plants, where CO2 is directly fixed into a 3-carbon molecule (3-PGA) in the Calvin cycle.

   - C4 photosynthesis: Found in plants like corn and sugarcane, C4 photosynthesis separates the initial CO2 fixation step from the Calvin cycle, allowing these plants to conserve water and avoid photorespiration in hot, dry climates.

   - CAM photosynthesis: Found in plants like cacti and succulents, CAM photosynthesis involves opening stomata at night to fix CO2, minimizing water loss during the day. This adaptation is useful in arid environments where water is scarce.

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These explanations should help clarify the process of photosynthesis and how different plants adapt to their environments!

Here’s a simple and clear breakdown of your study guide:

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### Vocabulary Definitions:

- Sugar: A simple carbohydrate. Example: glucose, fructose.

- Fatty Acid: A long hydrocarbon chain that is a building block of lipids. Example: palmitic acid.

- Nucleotide: A building block of nucleic acids. Example: adenine, thymine, cytosine, guanine (DNA).

- Amino Acid: The building block of proteins. Example: glycine, alanine.

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### Macromolecules:

1. Sugar → Carbohydrate (e.g., glucose forms starch or glycogen).

2. Fatty Acid → Lipid (e.g., fatty acids form triglycerides).

3. Amino Acid → Protein (e.g., amino acids form polypeptides, then proteins).

4. Nucleotide → Nucleic Acid (e.g., nucleotides form DNA or RNA).

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### Study Guide Questions:

1. Carbohydrates:

   - Glycogen: A storage form of glucose in animals.

   - Starch: A storage form of glucose in plants.

   - Chitin: A structural component in the exoskeletons of arthropods.

   - Cellulose: A structural component in plant cell walls, providing rigidity.

   Comparison:  

   - Glycogen and starch are energy storage molecules (in animals and plants, respectively).  

   - Chitin and cellulose are structural carbohydrates, providing support and strength (in animals and plants, respectively).

2. Saturated vs. Unsaturated Fats:

   - Saturated Fats: No double bonds between carbon atoms; solid at room temperature. Example: butter, animal fats.

   - Unsaturated Fats: One or more double bonds between carbon atoms; liquid at room temperature. Example: olive oil, fish oils.

3. Important Functions of Lipids:

   - Energy Storage: Lipids store energy for long-term use.

   - Cell Membranes: Phospholipids make up the cell membrane.

   - Insulation: Lipids help in heat retention and protecting organs.

   - Hormone Production: Some lipids are involved in making hormones (like steroids).

4. Why Don’t Fats Dissolve in Water?

   - Fats are hydrophobic (water-repelling) because their molecules are non-polar. Water molecules are polar, and since "like dissolves like," fats and water do not mix.

5. 4 Levels of Protein Structure:

   1. Primary Structure: The sequence of amino acids in a polypeptide chain.

   2. Secondary Structure: Folding of the polypeptide into structures like alpha-helices and beta-pleated sheets, stabilized by hydrogen bonds.

   3. Tertiary Structure: The 3D shape of the protein formed by further folding, involving interactions like hydrogen bonds, ionic bonds, and disulfide bridges.

   4. Quaternary Structure: The arrangement of multiple polypeptide chains in a functional protein.

6. Protein Denaturation:

   - Denaturation is when a protein loses its 3D structure due to external factors like heat or pH changes. This affects its function because the shape is essential for its activity.

7. Important Functions of Proteins:

   - Enzyme Catalysis: Proteins act as enzymes to speed up chemical reactions.

   - Transport: Proteins help transport molecules across cell membranes (e.g., hemoglobin transporting oxygen).

   - Structure: Proteins provide structural support (e.g., collagen in connective tissues).

   - Communication: Some proteins are involved in signaling (e.g., hormones).

   - Immune Function: Antibodies are proteins that help protect against infections.

8. Who Discovered the Structure of DNA?

   - James Watson and Francis Crick discovered the structure of DNA.  

   - Rosalind Franklin actually took the X-ray crystallography image (Photo 51) that was crucial for their discovery, but Watson and Crick received the Nobel Prize.

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This summary should give you a solid understanding of the key concepts from your study guide. Let me know if you'd like more information on any specific topic!

### Cell Organelles and Their Functions:

1. Plasma Membrane  

   - Function: Controls what enters and leaves the cell (like a gatekeeper).

   - Found in: All cells (prokaryotes, eukaryotes, plant, animal, fungi).

2. Cytoplasm  

   - Function: Jelly-like substance where all organelles are located and chemical reactions happen.

   - Found in: All cells (prokaryotes, eukaryotes, plant, animal, fungi).

3. Nucleus  

   - Function: Contains DNA, which carries genetic instructions. It's like the brain of the cell.

   - Found in: Eukaryotic cells (not in prokaryotes).

4. Ribosomes  

   - Function: Make proteins by linking amino acids together.

   - Found in: All cells (prokaryotes, eukaryotes, plant, animal, fungi).

5. Mitochondria  

   - Function: The "powerhouse" of the cell, converting food into energy (ATP).

   - Found in: Eukaryotic cells (plant, animal, fungi).

6. Cytoskeleton  

   - Function: Provides structure, shape, and helps with cell movement.

   - Found in: All cells (prokaryotes, eukaryotes, plant, animal, fungi).

7. Rough Endoplasmic Reticulum (Rough ER)  

   - Function: Helps make and transport proteins; it's rough because it has ribosomes on its surface.

   - Found in: Eukaryotic cells (animal, plant, fungi).

8. Smooth Endoplasmic Reticulum (Smooth ER)  

   - Function: Makes lipids (fats) and detoxifies harmful substances.

   - Found in: Eukaryotic cells (animal, plant, fungi).

9. Golgi Apparatus  

   - Function: Sorts, modifies, and packages proteins and lipids for transport.

   - Found in: Eukaryotic cells (animal, plant, fungi).

10. Vesicles  

    - Function: Small bubbles that transport materials inside the cell or out of the cell.

    - Found in: Eukaryotic cells (animal, plant, fungi).

11. Lysosomes  

    - Function: Contains digestive enzymes to break down waste and old cell parts.

    - Found in: Mostly animal cells, but some plant cells.

12. Cell Wall  

    - Function: Provides structure and protection; it helps maintain the shape of the cell.

    - Found in: Plant cells, fungi, and prokaryotes (not in animal cells).

13. Chloroplast  

    - Function: Uses sunlight to make food through photosynthesis (turns sunlight into sugar).

    - Found in: Plant cells (and some algae).

14. Central Vacuole  

    - Function: Stores water, nutrients, and waste. It also helps the plant maintain its shape.

    - Found in: Plant cells.

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### Study Guide Questions:

1. Characteristics Shared by All Cells  

   - All cells have DNA (genetic material), a plasma membrane (outer boundary), and cytoplasm (the gel-like interior substance).

2. Compare and Contrast Prokaryotes and Eukaryotes  

   - Prokaryotes: 

     - Simple, small cells.

     - No nucleus; DNA is free in the cell.

     - No membrane-bound organelles.

     - Example: Bacteria.

   - Eukaryotes:

     - Larger, more complex cells.

     - Have a nucleus where DNA is stored.

     - Have membrane-bound organelles (like mitochondria, Golgi apparatus).

     - Example: Animal cells, plant cells, fungi cells.

3. Endosymbiont Hypothesis for the Origin of Eukaryotic Cells  

   - This hypothesis suggests that eukaryotic cells originated when one cell engulfed another cell (a prokaryote). Over time, the engulfed cell became an organelle (like mitochondria or chloroplasts) in the host cell. Evidence includes the fact that these organelles have their own DNA and can reproduce on their own, like prokaryotes.

4. Compare and Contrast Plant Cells and Animal Cells  

   - Plant Cells:

     - Have a cell wall for structure.

     - Contain chloroplasts for photosynthesis.

     - Have a large central vacuole for storing water.

   - Animal Cells:

     - Do not have a cell wall.

     - Do not have chloroplasts (no photosynthesis).

     - Have small, temporary vacuoles.

5. Label the Cell Parts of an Animal Cell  

   - Plasma membrane: Outer boundary of the cell.

   - Nucleus: Contains DNA.

   - Cytoplasm: Gel-like substance.

   - Mitochondria: Powerhouse of the cell.

   - Ribosomes: Make proteins.

   - Golgi apparatus: Packages proteins.

   - Lysosomes: Break down waste.

   - Vesicles: Transport materials.

   Comparison with Plant Cell:

   - Plant cells also have the same basic parts (plasma membrane, nucleus, cytoplasm, etc.) but additionally have a cell wall, chloroplasts, and a large central vacuole.

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This should help with understanding the basic functions of cell parts and comparing different cell types!

Vocabulary Definitions:

1. Energy:  

   - The capacity to do work or cause change. Energy exists in different forms, such as kinetic, potential, chemical, and more.

2. Work:  

   - The transfer of energy through motion. Work is done when a force causes an object to move.

3. Kinetic Energy:  

   - Energy of motion. For example, a moving car, running, or a bouncing ball all demonstrate kinetic energy.

4. Potential Energy:  

   - Stored energy due to an object's position or structure. For example, a book on a shelf has potential energy due to its height.

5. Chemical Energy:  

   - Energy stored in the bonds of chemical compounds. This energy is released or absorbed during chemical reactions. For example, food and fuel store chemical energy.

6. Free Energy:  

   - The amount of energy available to do work in a system. It’s the energy that can be used by a cell for activities like growth or movement.

7. Activation Energy:  

   - The energy required to start a chemical reaction. It’s like a "push" to get the reaction going.

8. Enzyme:  

   - A protein that speeds up (catalyzes) chemical reactions by lowering the activation energy required.

9. Substrate:  

   - The substance an enzyme acts upon in a chemical reaction. The enzyme binds to the substrate to form a product.

10. Reactants vs. Products:  

    - Reactants: Substances that undergo a chemical reaction.  

    - Products: New substances formed as a result of a chemical reaction.

11. Entropy:  

    - A measure of disorder or randomness in a system. The second law of thermodynamics states that entropy tends to increase over time in a closed system.

12. Calorie vs. calorie:  

    - Calorie (capital C): A unit of energy used in nutrition. 1 Calorie = 1,000 calories.  

    - calorie (lowercase c): A small unit of energy used to measure heat; it’s the amount of energy needed to raise 1 gram of water by 1°C.

13. 1st Law of Thermodynamics:  

    - Energy cannot be created or destroyed; it can only be converted from one form to another. This is also known as the Law of Conservation of Energy.

14. 2nd Law of Thermodynamics:  

    - The total entropy of an isolated system always increases over time, and energy transformations are never 100% efficient. Some energy is always lost as heat.

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### Study Guide Questions:

1. Try to identify several different examples of energy in your daily life and classify them as kinetic or potential.  

   - Kinetic energy: A moving car, running, or a person riding a bike.

   - Potential energy: A book on a shelf, water stored in a dam, or a stretched rubber band.

2. Define chemical energy and explain how it is used.  

   - Chemical energy is the energy stored in the bonds of molecules. Our body uses it to power activities like movement, digestion, and cell function. For example, when we eat food, our body breaks down the food molecules (like glucose) to release chemical energy that we use for daily tasks.

3. Define metabolism and explain the difference between catabolism and anabolism.  

   - Metabolism refers to all the chemical reactions that occur within an organism to maintain life.  

   - Catabolism: The breakdown of larger molecules into smaller ones, releasing energy (e.g., digestion).  

   - Anabolism: The building of larger molecules from smaller ones, requiring energy (e.g., building muscle or DNA).

4. How do we measure the efficiency of a chemical reaction?  

   - The efficiency of a chemical reaction can be measured by how much energy is produced as useful work compared to how much energy is lost as heat. This is often described as the energy yield or efficiency ratio.

5. What does it mean when some energy is dissipated as heat in a chemical reaction?  

   - It means that during the reaction, not all of the energy was used to do work. Some of it was lost as heat energy, making the reaction less efficient. This aligns with the 2nd Law of Thermodynamics.

6. Be able to describe all the energy transformations in the "howling gummy bear" demonstration.  

   - In this demonstration, a gummy bear undergoes a chemical reaction when it reacts with potassium chlorate (KClO₃). The reaction releases chemical energy that is transformed into heat energy, causing the gummy bear to burn and release gases. This leads to an explosive, energy-releasing "howling" effect.

7. Define "activation energy" and be able to describe how enzymes lower activation energy.  

   - Activation energy is the energy required to start a chemical reaction. Enzymes are biological catalysts that speed up reactions by lowering the activation energy, making it easier for reactions to occur at lower temperatures.

8. Be able to describe real applications of the 1st and 2nd Laws of Thermodynamics.  

   - 1st Law (Conservation of Energy): In a power plant, chemical energy in fuel is converted into electrical energy. The total energy is conserved, though some is lost as heat.

   - 2nd Law (Entropy): In a car engine, energy is transformed from fuel into motion, but much of the energy is lost as heat, increasing the system's entropy.

9. What is ATP and how does it work to store energy in cells?  

   - ATP (Adenosine Triphosphate) is the main energy carrier in cells. It stores energy in the high-energy bonds between its phosphate groups. When the cell needs energy, ATP is broken down into ADP (Adenosine Diphosphate) and an inorganic phosphate, releasing energy that the cell can use for work.

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These explanations break down the concepts in simple terms to help you understand the vocabulary and questions about energy and its role in life processes!