Photosynthesis

Central Idea: process used by autotrophs to capture light energy & use it to power chemical reactions that convert carbon dioxide and water into oxygen and energy-rich carbohydrates.

Main Branches:

Light-dependent Reactions

• Occur in the thylakoid membrane of chloroplasts

• Require light energy and water

• Produce ATP, NADPH, and oxygen as byproduct

  • ATP and NADPH are used in the Calvin cycle

• Electron Transport Chain

  • Light first hits PSII & excites electron pair

  • PSII splits water and releases an electron and a hydrogen proton, oxygen gas is released as a byproduct

  • The excited electron moves on

  • The energy from e- allows the cytochrome to pump hydrogen protons across the thylakoid membrane to the lumen

  • Light hits PSI and re-excites electrons

  • e- move on & helps produce NADPH

  • Meanwhile, H+ goes across the thylakoid membrane through ATP Synthase (produces ATP)

  • ATP and NADH move to Calvin Cycle

• Calvin Cycle (Light-independent Reactions)

  • Occur in the stroma of chloroplasts

  • Does not require light directly

  • Use ATP, NADPH, and carbon dioxide

  • Produce glucose and regenerate starting molecules (NADPH → NADP+) (ATP → ADP)

    • Carbon fixation

      • Carbon dioxide enters & combines with 5-carbon compound already present.

      • A 3-carbon compound continues to cycle (every 6 carbon dioxides that enters, 12 3-carbon compounds are produced)

    • Reduction

      • Mid cycle, 2 of 12 3-carbon compounds are removed to become the building blocks for sugar production (requires ATP and NADPH)

    • Regeneration

      • Remaining 10 molecules convert back to 6 5-carbon molecules

Cell Organization

Central Idea: Cell Structure and Function

• Cell: Basic unit of life

• Organelles: Specialized structures within a cell

Main Branches:

1. Prokaryotic Cells

   • Lack a nucleus

   • Simple structure

   • Examples: bacteria, archaea

2. Eukaryotic Cells

   • Have a nucleus

   • Complex structure

   • Examples: animals, plants, fungi

3. Characteristics of Living Things

   • Reproduce (sexual & asexual)

   • Biological inheritance is carried in DNA

   • Can grow & develop

   • Obtain materials & energy (metabolism)

   • Respond to environment (stimulus)

   • Homeostasis

   • Evolve

Prokaryotic Cells:

• Cell Wall

  • Provides shape and protection

  • Composed of bacteria

  • porous

• Cell Membrane

  • Controls entry and exit of substances

  • Phospholipid bilayer with embedded proteins

• Cytoplasm

  • Gel-like substance inside the cell

  • Contains enzymes and cellular structures

• Nucleoid

  • Region where DNA is located

  • Not enclosed by a membrane

• Ribosomes

  • Site of protein synthesis (follow DNA instructions)

  • Composed of RNA and proteins

  • Located on rough ER or in cytoplasm

Eukaryotic Cells:

• Nucleus

  • Contains DNA (in chromosomes in the form of chromatin)

    • Chromatin- a complex of DNA

  • Controls cell activities

  • Nucleolus- where ribosome assembly starts

  • Nuclear Membrane surrounds nucleus (porous)

• Cell Membrane

  • Selectively permeable barrier

  • Maintains cell shape

  • phospholipid bilayer- forms barrier to outside substances

• Cytoplasm

  • Fluid-filled region between nucleus and cell membrane

  • Contains organelles

• Endoplasmic Reticulum (ER)

  • Rough ER: Synthesis of proteins

  • Smooth ER: Lipid synthesis, detoxification of drugs

• Golgi Apparatus

  • Modifies, sorts, and packages proteins

  • Forms vesicles for transport (transports proteins)

• Mitochondria

  • Produces energy (ATP) through cellular respiration

  • Double membrane structure

• Chloroplasts

  • Found in plant cells

  • Site of photosynthesis

  • Contains chlorophyll (absorbs sunlight)

• Lysosomes

  • Contains digestive enzymes

  • Breaks down waste materials

  • Filled with enzymes

• Vacuoles

  • Stores water, nutrients, and waste

  • Large central vacuole in plant cells

    • pressure makes plant cell ridged (so can support flowers)

  • Contractile Vacuole- pumps water out of cell

• Cytoskeleton

  • Provides structural support and cell movement

  • Made of microtubules, microfil

    • Microfilaments

      • Thread-like structures made up of actin (a protein)

      • Helps cell move

    • Microtubles

      • Hollow structures made of tubulins (a protein)

      • Helps with cell division

      • Builds cilia and flagella

Cellular Respiration & Fermentation

Central Idea: Process of energy conversion that releases energy from food in the presence of oxygen

Cellular Respiration:

• Aerobic Respiration

  • Glycolysis

  • Krebs Cycle (Citric Acid Cycle)

  • Electron Transport Chain

• Anaerobic Respiration

  • Lactic Acid Fermentation

  • Alcoholic Fermentation

Glycolysis:

• Sugar Breaking

• Two ATP invested in cycle (at the end has a net gain of 2)

• Glucose is broken into 2 molecules of pyruvic acid

• 4 e- are passed to NAD+ which makes NADH (takes e- to ETC)

Krebs Cycle (Citric Acid Cycle):

• Pyruvic acid (from glycolysis) broken into carbon dioxide

• 1 Carbon dioxide is released

• Rest of pyruvic acid joins acetic acid which joins co-enzyme A to form Acetyl CoA

• Acetyl CoA gives 2 carbon Acetyl groups to cycle to 4-carbon molecule already present (which produces a 6-carbon molecule called Citric Acid)

• Releases carbon dioxide

• Produces ATP, NADH, and FADH₂ (goes to ETC)

Electron Transport Chain:

• Uses e- to synthesize ATP from ADP

• At the end, an enzyme combines e- with a hydrogen & oxygen to form water

• e- send H+ across the membrane- the force makes ATP Synthase spin

• During each rotation the enzyme attaches a phosphate group making ADP → ATP

Fermentation:

• Lactic Acid Fermentation

  • Pyruvic acid + NADH → Lactic acid + NAD+

  • Muscle cells during intense exercise

• Alcoholic Fermentation

  • Yeast cells

  • Pyruvic acid + NADH → Alcohol + Carbon Dioxide + NAD+

  • Production of ethanol and carbon dioxide

Long-Term Energy Storage:

• Exercise <90 seconds

• Cellular respiration only way to produce enough ATP

• stores energy in muscle cells & tissues

• After 15-20 mins, breaks down fats

Short-Term Energy Storage:

• Glycogenolysis

  • Breakdown of glycogen to glucose

• Glucose uptake

  • Transport of glucose into cells

• ATP hydrolysis

  • Conversion of ATP to ADP + Pi for immediate energy release

Note: This mind map provides a simplified overview of the topics. Further details and connections can be explored within each branch and sub-branch.

Biochemistry

Central Idea: idk

Macromolecules

• Carbohydrates

  • Carbon, hydrogen, oxygen (1:2:1)

  • Structural support & protection

  • Immediate energy

  • Monomer = monosaccharides (ex. glucose, fructose)

  • Hydrophilic

• Proteins

  • Monomer = amino Acids

  • Carbon, hydrogen, oxygen, nitrogen

  • Peptide bonding is chemical bond between molecules (covalent)

  • Control rate of reaction (catalyst)

  • Regulate processes

  • Form important structures

  • Fight disease

  • Enable cell interactions

  • Hydrophilic

• Lipids

  • Carbon, hydrogen, oxygen

  • Hydrophobic

  • Store energy (long term)

  • Form parts of membranes

  • Water proof (waxy covering)

  • No specific monomer

  • Glycerol (docking molecule)

    • Combines with fatty acids to form lipids

• Nucleic Acids

  • Carbon, hydrogen, oxygen, nitrogen, phosphorus

  • Monomer = nucleotides

  • 2 kinds:

    • RNA

    • DNA

  • Can be both, hydrophilic and hydrophobic

Properties of Water

• Water

  • Polar

  • Forms hydrogen bonds (weaker then covalent & ionic)

• Cohesion

  • Surface tension

  • Attraction between molecules of same substance

• Adhesion

  • ‘Sticking together’ of substances

  • Capillary action = if adhesion causes something to go against gravity

  • Attraction between molecules of different substances

• Heat Capacity

  • Amount of energy needed to raise waters temperature by making molecules move faster

  • Protects organisms from drastic temperature changes

• Solution

  • All components are equally distributed

  • Water polarity allows it to dissolve ionic compound & other polar molecules

  • When certain amount of water dissolves all of the solute it can, solution is saturated

• Suspensions

  • Materials that don’t dissolve in water but separate in small pieces that don’t settle

  • Movement of water molecules keeps them suspended (ex. blood)

• Mixture

  • Material composed of 2 or more elements that are physically mixed but not chemically combined

  Acids

• pH scale

  • Ranges from 0-14

  • At pH of 7, OH- and H+ ions are equal

  • Solutions with pH above 7 are ‘basic’ (have more OH-)

  • Solutions with pH below 7 are ‘acidic’ (have more H+)

  • Factor of 10 (ex. a solution of pH 4 has 10x as many H+ ions as solution with a pH of 5)

• Bases

  • basic solutions

  • strong bases are 11-14 pH

• Buffers

  • Help control pH levels

  • Internal pH of most cells is 6.5 - 7.5

Enzymes

• Active Site

  • Where substrate binds to enzyme

• Substrate

  • Molecule that binds to enzyme

  • What enzyme breaks down OR builds up

    • For reaction to occur- reactants must collide with each other with sufficient energy that existing bonds will be broken so new ones can form

• Enzyme Function

  • Catalysis

    • if activation energy is too high or too slow, catalysis speed up reactions

• Factors Affecting Enzyme Activity

  • Temperature

  • pH

  • Substrate Concentration

  • Enzyme Concentration