AP Biology Notes - Chemistry of Life to Ecology

1.1 - Structure of Water and Hydrogen Bonding

• Water is fundamental for life, essential for the structure and function of cells and organisms.

• Polarity: Water (H₂O) is polar due to unequal electron sharing between oxygen and hydrogen. Oxygen has a partial negative charge ($\delta$⁻), hydrogens have partial positive charges ($\delta$⁺).

• Two polar covalent bonds hold H₂O together.

• Hydrogen Bonds: Weak attractions between water molecules or other polar substances. They break and reform constantly.

• Cohesion: Water molecules strongly attract each other due to hydrogen bonding, creating high surface tension.

• Adhesion: Water attracts other polar substances, essential for capillary action (e.g., water movement in plants).

• High Specific Heat: Water absorbs or releases much heat with small temperature changes, moderating temperatures.

• High Heat of Vaporization: Much energy is needed to convert liquid water to vapor, allowing evaporative cooling.

• Universal Solvent: Water is an excellent solvent for polar and ionic substances, crucial for biological processes.

• Surface tension measures the difficulty to stretch or break a liquid's surface. Water has high surface tension because of strong cohesive forces.

1.2 - Elements of Life

• All living organisms and their environments comprise the same basic chemical elements.

• Living things must continually exchange matter with their environment to maintain life processes.

• Intake:

  • Oxygen (O₂) for cellular respiration.

  • Nutrients (e.g., glucose) for energy and building blocks.

  • Water (H₂O) as a solvent and for reactions.

  • Ions (e.g., sodium, potassium) for cellular functions.

• Output:

  • Carbon dioxide (CO₂) as a waste product of respiration.

  • Wastes (e.g., urea) to remove metabolic byproducts.

  • Water (H₂O) through respiration, excretion, and other processes.

  • Ions to maintain proper balance.

• Key Life Processes: Respiration, synthesis, growth, division.

• Carbon is the backbone of life; its ability to form four covalent bonds allows for diverse organic compounds.

• Major Classes of Biological Molecules

  • Carbohydrates: Carbon, hydrogen, and oxygen (CHO); for energy and structural support.

  • Lipids: Carbon, hydrogen, and oxygen (CHO); include fats, oils, and waxes; store energy, insulate, and form cell membranes.

  • Proteins: Carbon, hydrogen, oxygen, nitrogen (CHON), and sometimes sulfur; perform diverse functions including as enzymes, structural components, and transporters.

  • Nucleic Acids: Carbon, hydrogen, oxygen, nitrogen, and phosphorus (CHONP); store and transmit genetic information (DNA and RNA).

• Isomers are molecules with the same chemical formula but different structural arrangements, leading to differences in function.

  • Structural Isomers: Different atom arrangements. Glucose and fructose (C₆H₁₂O₆) are examples.

  • Cis-Trans Isomers: Occur with double bonds. "Cis" means same side, "trans" means opposite sides. They can have distinct biological effects.

  • Enantiomers (Optical Isomers): Mirror images, with a central carbon bonded to four different groups. They interact differently in biological systems.

• Importance of Isomers in Biology:

  • Enzyme Specificity: Enzymes recognize specific isomers.

  • Drug Design: Isomers have varying effects; some are beneficial, others harmful.

  • Biological Activity: Enantiomers can have different biological activities.

1.3 - Introduction to Biological Macromolecules

• Living organisms rely on four major classes of large biological molecules (macromolecules):

  • Carbohydrates

  • Lipids

  • Proteins

  • Nucleic Acids

• These are macromolecules because they are relatively large compared to other molecules.

• Polymers and Monomers:

  • Many macromolecules are polymers—long chains of repeating units called monomers.

  • Monomers are individual beads, and polymers are the entire necklace.

• Building and Breaking Polymers:

  • Dehydration Synthesis (Condensation Reaction): Monomers link to form polymers by removing a water molecule.

  • Hydrolysis: Polymers break down into monomers by adding a water molecule.

1.4 - Properties of Biological Macromolecules

• Polymers: Long chains built from monomers.

• Monomers: Determine macromolecule properties.

• Carbohydrates:

  • Monosaccharides: Simple sugars (e.g., glucose, fructose) used for immediate energy.

  • Disaccharides: Two monosaccharides joined by a glycosidic linkage (e.g., sucrose, lactose, maltose).

  • Polysaccharides: Long chains of monosaccharides, like starch for energy storage or cellulose for structural support.

• Proteins:

  • Amino Acids: Monomers with 20 types, each with a unique R-group determining properties: nonpolar (hydrophobic), polar (hydrophilic), charged (acidic or basic).

  • Peptide Bonds: Amino acids link together via peptide bonds, forming polypeptides.

  • Protein Structure and Function: Amino acid sequence determines a protein's 3D shape, crucial for its specific function (e.g., enzymes, structural proteins, transport proteins).

• Lipids:

  • Nonpolar, hydrophobic molecules that don't mix well with water.

  • Fats: Energy storage, composed of glycerol and fatty acids. Unsaturated fats have double bonds, causing kinks and making them liquid at room temperature. Saturated fats have single bonds, allowing tight packing and solid form at room temperature.

  • Phospholipids: Major component of cell membranes with polar (hydrophilic) heads and nonpolar (hydrophobic) tails.

  • Steroids: Lipids with a ring structure, such as cholesterol and hormones.

• Nucleic Acids:

  • Nucleotides: Monomers consisting of 5-carbon sugar (deoxyribose in DNA, ribose in RNA), phosphate group, and nitrogenous base (A, G, C, T in DNA, or U in RNA).

  • DNA: Stores genetic information in a double-stranded helix.

  • RNA: Involved in protein synthesis and other cellular functions; single-stranded.

1.5 - Structure and Function of Macromolecules

• Carbohydrates

  • Polysaccharides: Polymers of monosaccharides linked by glycosidic bonds. Can be linear or branched.

    • Energy Storage: Starch (plants), Glycogen (animals)

    • Structural support: Cellulose (Plant cell walls), Chitin (exoskeleton insects/cell walls of fungi)

• Proteins

  • Primary Structure: Linear sequence of amino acids determined by genetic code (DNA). Influences all other levels of protein structure.

    • Polypeptides: Chains of amino acids connected by peptide bonds.

    • Peptide Bonds: Bonds between carboxyl group (-COOH) of one amino acid and amino group (-NH₂) of another.

    • R-Group Importance: Properties of each amino acid R-group determine how polypeptide folds and interacts, dictating protein function.

  • Coiling and folding due to hydrogen bonds between the amino and carboxyl groups in the backbone of the polypeptide.

    • Alpha Helix: Spiral-shaped structure where hydrogen bonds form every fourth amino acid.

    • Beta Pleated Sheet: Flat, sheet-like structure where hydrogen bonds form between parallel or antiparallel stretches of the polypeptide chain.

  • Tertiary structure

    • Hydrophobic interactions: Nonpolar side chains cluster together in the protein's interior, away from water.

    • Disulfide bridges: Covalent bonds between sulfur atoms in the side chains of cysteine amino acids.

    • Hydrogen bonds and ionic bonds between other side chains.

  • Quaternary Structure

    • Multiple Polypeptides: Some proteins consist of multiple polypeptide subunits that come together to form a functional complex.

    • Example: Hemoglobin, the protein responsible for carrying oxygen in blood, consists of four polypeptide subunits.

    • Function: All four levels of protein structure (primary, secondary, tertiary, and quaternary) contribute to the protein's final shape and function.

1.6 - Nucleic Acids

• DNA Structure: Double Helix.

  • Polynucleotide: nucleotides linked by phosphodiester bonds.

  • Phosphodiester Bond: Links sugar of one nucleotide to phosphate group of next.

  • Antiparallel Strands: Run in opposite directions (5' to 3' and 3' to 5'). Carbon numbers in deoxyribose sugar.

  • Complementary Base Pairing: Adenine (A) pairs with Thymine (T), Guanine (G) pairs with Cytosine (C).

  • Purines: Adenine (A) and Guanine (G), two-ring structures.

  • Pyrimidines: Cytosine (C), Thymine (T), and Uracil (U), one-ring structures.

• DNA replication occurs in the 5' to 3' direction, adding nucleotides to the 3' end.

• DNA strands are antiparallel, replication is continuous on the leading strand and fragmented on the lagging strand.

• DNA vs RNA

  • DNA: Double Helix, Deoxyribose lacks -OH, Bases A,G,C,T. Stores genetic information

  • RNA: Single Strand, Ribose has -OH, Bases A,G,C,U. Involved in protein synthesis

2.1 - Cell Structure: Subcellular Components

• Basic Cell Types: Eukaryotic and Prokaryotic

  • Eukaryotic Cells: Contain DNA within a nucleus and membrane-bound organelles.

  • Prokaryotic Cells: Lack a nucleus and membrane-bound organelles.

• Common Cellular Components:

  • Cytosol: Jelly-like substance supporting subcellular components.

  • Ribosomes: Complexes of RNA and protein for protein synthesis.

  • Plasma Membrane: Selectively permeable barrier regulating entry and exit of substances.

• Organelles in Eukaryotic Cells:

  • Endoplasmic Reticulum (ER): Network of membranes continuous with the nuclear membrane.

    • Smooth ER: Lacks ribosomes; synthesizes lipids and detoxifies toxins.

    • Rough ER: Has ribosomes; processes and packages proteins into vesicles.

  • Golgi Complex: Modifies, sorts, and packages proteins received from the ER; dispatches them to other locations.

  • Mitochondria: Powerhouse of the cell where cellular respiration occurs, generating ATP; inner membrane folded into cristae.

  • Lysosome: Contains hydrolytic enzymes for breaking down macromolecules.

  • Vacuole: Stores nutrients and regulates water content; supports growth in plant cells.

  • Chloroplasts: Conduct photosynthesis in plants and algae, converting solar energy into chemical energy.

2.2 - Cell Structure and Function

• Each subcellular component is optimized for its specific function.

• Key Cellular Components and Their Functions:

  • Lysosomes: Digest molecules and recycle cellular materials.

  • Endoplasmic Reticulum (ER):

    • Synthesizes proteins and lipids.

    • Transports molecules and provides structural support.

  • Vacuoles:

    • Store molecules and waste products.

    • Regulate water content.

  • Mitochondria: Powerhouses of the cell.

    • Metabolic reactions and ATP synthesis.

    • Aerobic Cellular Respiration: Takes place in mitochondria.

    • Oxidative Phosphorylation: Occurs along inner membrane.

    • Krebs/Citric Acid Cycle: Occurs in mitochondrial matrix.

  • Chloroplasts: Essential for photosynthesis.

    • Light-Dependent Reactions: Capture solar energy in thylakoid membranes.

    • Calvin Cycle (Dark Reactions): Focus on sugar synthesis in stroma.

2.3 - Cell Size

• Cells must exchange materials with their environment to obtain nutrients, eliminate waste, and manage energy.

• Impact of Cell Size:

  • Efficiency of Diffusion: Diffusion is less efficient in larger cells.

  • Advantage of Smaller Cells: Better material exchange due to favorable surface area to volume ratio.

• Surface Area to Volume Ratio (SA):

  • Ability to exchange materials dependent on surface area relative to volume.

  • SA expressed as SA or S/V; higher ratio indicates greater capacity for exchange.

• Specialized structures like microvilli and cristae enhance exchange.

2.4 - Plasma Membrane Structure and Function

• The plasma membrane defines the cell boundary and maintains a stable internal environment.

• Selective Permeability:

  • Certain substances pass through more easily because of it's structure.

• Fluid Mosaic Model:

  • Lipids and proteins can move laterally within the membrane.

  • Animal cell membrane includes proteins, glycoproteins, and sterols embedded within a phospholipid bilayer.

  • Phospholipids: Amphipathic nature with hydrophilic heads and hydrophobic tails arranging themselves in a bilayer.

• Membrane Fluidity:

  • Fatty Acids: Unsaturated fatty acids increase fluidity by preventing tight packing.

  • Cholesterol: Enhances membrane fluidity.

2.5 - Membrane Permeability

• Plasma membrane separates cells from their surroundings and maintains a stable internal environment.

• Selective Permeability:

  • Some substances cross more easily than others.

  • Hydrophobic fatty acid tails obstruct passage of polar molecules.

  • **Permeability to Molecules:

    • CO2 and O2 move freely because of nonpolar nature.

    • Large polar and charged molecules require transport mechanisms.

    • Transport proteins (channel and transport) facilitate movement of large polar molecules and ions across the membrane.

    • Water traverses membrane through aquaporins.

• The cell wall (primarily cellulose) in plant cells provides structural support and acts as a boundary, controlling permeability.

2.6 - Membrane Transport

• Diffusion Fundamentals: High to low concentration.

• Concentration Gradient: Density increases or decreases.

• Equilibrium: No net diffusion.

• Types of Cellular Transport:
  * Passive Transport: No energy required. Diffusion.
  * Active Transport: Requires energy (ATP) to move substances against concentration gradient.

• Vesicle Transport: membranes that form small sacs that help import and export large molecules.

  • Exocytosis: Secretion of molecules via vesicle fusion with plasma membrane.

  • Endocytosis: Intake of molecules by vesicle fusion with plasma membrane.

    • Phagocytosis: Engulfing solid particles into a food vacuole, which fuses with lysosomes.

    • Pinocytosis: Ingestion of extracellular fluids through small vesicles.

  • Endomembrane system works closely with ER and Golgi regulate material transport via vesicles.

2.7 - Facilitated Diffusion

• Small nonpolar molecules pass through lipid bilayer via passive diffusion.

• Facilitated Diffusion and Active Transport:
  * Facilitated Diffusion: Form of passive transport aided by transport proteins.
  * Aquaporins: Channel proteins for rapid water transport.
  * Active Transport: energy required to move molecules against their gradient

• Electrochemical Gradient:
  * Polarization of Membranes: This electrical potential difference is crucial for charged substances.
  * Acts as a battery across the cell's membrane.
  * Resting Potential: Around -70 mV for many cells

• Active Transport Mechanisms:
  * Sodium-Potassium Pump: Generates voltage by exchanging three sodium ions (Na+) out for two potassium ions (K+) in, using ATP.
  * Electrogenic pumps = Voltage across the membrane. example: Proton pump, actively transports hydrogen ions (H+) out of the cell.
  * Cotransport: H+ pumped out and diffuse back in through sucrose cotransporter, bringing sucrose into cell

2.8 - Tonicity and Osmoregulation

• Osmosis Basics:
  * Definition: Water from high concentration (lower solute) to lower concentration (higher solute).

• Tonicity and Its Effects:
  * Tonicity: Ability of surrounding solution to cause cell to gain/lose water, based on nonpenetrating solute concentration.
  * Isotonic Environment: No net water movement into or out of cell; balanced.
  * Hypertonic Environment: Higher solute concentration outside causes water to exit cell.
  * Hypotonic Environment: Lower solute concentration outside causes water to enter cell.

• Cellular Responses in Different Environments:
  * Animal Cells: Prefer isotonic conditions.
  * Plant Cells in Hypotonic Conditions: uptake of waters -> turgidity essential structural support.
  * States: Turgid, Flaccid, Plasmolysed

Understanding Water Potential in Cellular Processes

• Water Potential: Predicts the direction of water flow.

• General Principle: Water moves from regions of higher to lower water potential

• Solute Potential: Always 0 or negative, influenced by solute concentration.

  • $$Ψs =−iCRT$$

    • i: Ionization constant

    • C: Molar concentration

    • R: Pressure constant, 0.0831 liter MPa per mole K

    • T: Temperature in Kelvin (Celsius+273)

• Solute potential of pure water is 0.

• Pressure potential of a solution in open air (like a beaker) is 0.

• Ionization constant for salt (NaCl) is 2.

• Ionization constant for sugar (e.g., glucose) is 1.

2.9 - Mechanisms of Transport

• Passive Transport:

  • No cellular energy required.

  • Moves with the concentration gradient.

  • Small, nonpolar molecules.

• Facilitated Diffusion:

  • Requires membrane proteins.

  • Substances move down the concentration gradient.

  • Requires channel proteins for transport.

  • Ion channels allow specific ions to pass through.

• Active Transport:

  • Moves against concentration gradient; (low to high)

  • Large, polar and charged molecules.

  • Requires ATP.

  • Electrogenic pumps (Proton Pumps and Na+/K+)

  • Cotransport: Energy in one molecule's gradient to transport another.

  • Exocytosis and Endocytosis: Large quantities of materials using vesicles.

2.10 - Cell Compartmentalization

• Prokaryotic Cells:

  • Lack membrane-bound organelles.

  • Less compartmentalization. Contains specialized structures that are not separated by membranes

• Eukaryotic Cells:

  • Nucleus and membrane-bound organelles.

  • Separate enzymatic reactions within cellular environments.

  • Increased surface area enhances efficiency.

• Compartmentalization optimizes enzymatic reactions, controls processes, and prevents interference.

2.11 - Origins of Cell Compartmentalization

• Endosymbiosis: Early eukaryotic cells engulfed non-photosynthetic prokaryotic cell becomes integral part of host

• Engulfed cell turns into mitochondria and chloroplasts

• Evidence Supporting Endosymbiosis: These organelles

  • Dual Membranes

  • Genetic Autonomy: Contain own ribosomes and circular DNA.

  • Reproductive independence

3.1/3.2 - Enzyme Structure and Catalysis

• Metabolism: All chemical reactions occurring within an organism.

• Organisms require energy and macromolecules.

• Metabolic Pathways:
  * Catabolic Pathways: Break down complex molecules; release energy.
  * Anabolic Pathways: Use energy to synthesize complex molecules.

• Enzymes act as catalysts, speeding up chemical reactions.
  * Example: Lactase catalyzes lactose hydrolysis.

• Activation Energy (EA): The initial energy needed to start a chemical reaction.
  • Enzyme Activity: Function by lowering the activation energy required for a reaction.

• By reducing activation energy, enzymes allow reactions to proceed more rapidly and costs are lowered
  • Enzymes provide a platform for reactants to come together in an optimal orientation to help facilitate the formation of transition states

  • Enzyme Specificity: enzymes only catalyze one specific reaction. Ex. Lactase catalyzes the breakdown of lactose.

  • At Active Site Binding Substrate is transformed into products Reaction Sequence generalized as $E + S → ES → EP → E + P$

    • E: Enzyme

    • S: Substrate

    • ES: Enzyme-substrate complex

      • EP: Enzyme-product complex

    • P: Product

3.3 - Environmental Impacts on Enzyme Function

• Enzyme activity influenced by temperature, pH, substrate concentration, inhibitors.

• Temperature Effects

  • Reaction Rate: Rate is increase with higher temp. Substrates collide more with active sites

  • Denaturation : excessively high temperatures disrupt , causing denaturation

    • Protein loses functional shape and becomes inactive.

    • Enzymes function within specific pH ranges.

  • Deviations cause denaturation by disrupting hydrogen bonding. Ex. Amylase =7, Pepsin =2, Trypsin= 8

• Inhibitors play crucial roles in regulating which enzymatic reactions occur within a cell

• Allosteric Regulation occurs when a molecule binds to places other than the active site and effects the functions of the enzyme.

3.4 - Cellular Energy

• Continuous energy input exceeds output

• Energy converted to another form. Energy not destroyed

• Exergonic Reactions: Reactions with a net release of energy = spontaneous.

• Endergonic Reactions: Reactions that absorb free energy require input = nonspontaneous.

• Energy Coupling exergonic reactions used to drive endergonic reactions

3.5 - Photosynthesis

• Converts light energy into chemical energy, stored in sugars and other organic molecules and can nourish other organisms.

• evolved around 3 billion years ago in prokaryotic cyanobacteria
  Simplified Reaction: CO2 + H2O + Light → C6H12O6 + O2

• Two stages of photosynthesis, focusing on the primary processes and their locations within the chloroplast:

  • Process: Light Reactions

    • Location: Thylakoid membranes

      • Energy source is Sunlight, the converting it to chemical energy and spliting water causing oxygen evolution as an output.

  • Calvin Cycle

    • Location is the stroma of the Chloroplasts which will use ATP and NADPH to convert $CO_2$ to Glucose.

• Photosystems are composed of a reaction center complex surrounded by multiple light-harvesting complexes that contain chlorophyll.

  • Molecule is reduced as it gains electrons with each process.

  • Photosystem II: Water is split to replace the lost electron, releasing hydrogen ions and oxygen.

  • Proton Gradient: Electrons move from Photosystem II to Photosystem I, pumping hydrogen ions into the thylakoid. Drives ATP Synthase. ADP + P -> ATP

• The Calvin cycle, converts carbon dioxide into organic carbohydrates. During the energy and reduction step

  • ATP Supplies the energy

  • NADPH provides the reducing power Reactions:

    • Carbon Fixation:

  • Reduction

  • Regeneration
    RUBISCO involved in CO2 addition, Regeneration and Carbon Fisation

3.6 - Cellular Respiration

Cellular Respiration and Fermentation are catabolic process used to make that release ATP

• Types of Cellular Respiration:

  • Aerobic Respiration: O2 is required to convert organic fuel into ATP, carbon dioxide, and water. $C6H{12}O6+6O2 -> 6CO2 +6H2O + ATP$

    • Glycolysis: Occurs in the cytosol

  • Krebs Cycle occurs in the Mitochondria

  • Electron Transport Chain: Electrons from NADH and FADH2 are transferred through a series of proteins (Oxidative phosphorylation)

    • Fermentation: Anaerobic process where organic fuels are degraded without the use of oxygen.

    • Phosphorylation: Process of adding a phosphate group to ADP to form ATP

      • Substrate-Level Phosphorylation: Direct transfer of a phosphate group to ADP

      • Oxidative Phosphorylation: electrons are used to pump protons across the mitochondrial membrane

• Krebs Cycle occurs in the mitochondrial matrix.

  • releases $CO_2$ as a byproduct from the decarboxylation of organic intermediates.

  • The cycle generates 1 ATP per turn through substrate-level phosphorylation.

  • It also produces 3 molecules of NADH and 1 molecule of FADH2.

• The electron transport chain is located along the inner mitochondrial membrane

  • releases energy to make ATP during oxidative phosphorylation (Chemiosmosis)

• * Cellular Communication

4.1 Cell Communication

 *Essential for cellular coordination both unicellular and multicellular
 *Cells Communicate through generating, transmitting, receiving, and responding to chemical signals.

There is Direct communication through junctions connecting the cytoplasm of cells and triggering a response.

These immune also show Direct Communication through binding molecules
Local Communication
*Autocrine Signaling, sending signals to themselves
Paracrine signaling where cells secrete signaling
neurotransmitters between neurons
Long distance Signaling with includes
Synaptic Signaling in the nervous system
Endocrine Hormonal signaling which is very slow and causes hormone to be released, then transported the cells which will then regulate processes. Example is with the pancreas to control glucose levels with the use of Insulin and glucagon

4.2 Introduction to Signal Transduction

The process by which external stimuli is converted to
cellular response
*Reception
*Transduction
*Response
ligand molecule that binds and then a receptor that transforms the signal through reactions until the response is generated.
Intracellular receptors: Bind ligands that can cross through the membrane. Transmembrane receptor do not allow ligands that cannot cross the membrane.
GPCRs activate through hormone binding and GTP switching through G protein activation
Ligand Gated ion channels are activated by protein changing conformation, opening channels, and allowing diffusion that changes electrical potential. Good examples is shown in neuronal activity.
intracellular receptors

• Function in gene transcription: Steroid hormones bind to DNA and regulate transcription.
  Multistep processes allow small molecules to make a big impact! This is known as amplification:
  Control is achieved each step down regulation pathway (Phosphorylation: Phosphate group attaching to a protein making it active) through a cascade to amplify down the chain
  There is also protein phosphatases which DEACTIVATE phosphated proteins
  Second messengers use more small molecules or ions that translate the signal through receptors
  Examples of second messengers is cAMP (cyclic AMP) which:
  *Derives from ATP through adenylate cyclase
  Can then use multiple proteins like protein kinases and amplify cells

4.3 Signal Transduction Examples

 *  In bacteria: cell Quorum sensing for population to monitor and change factors within the environment
 * Epi signaling to allow GPCR to create more 2nd messenger systems.
 *Can effect Gene expression and cell regulation: Mating and pheromones in mRNA transcription or the use of Ethelyne. The SRY protein is important for transcribing of genes for male hormones.

Epinephrine
Receptor
Activation of G protein by GTP binding Adenylyl Cyclase ATP to camp. Then to phosphorylation glycogen, then release into the body as Glucose

4.4 Changes in Signal Transduction Pathways

Alterations can happen at all levels. This will lead to pathological indications
Cancer can occur due to a growth factor stimulation (which is bad)
Can Target through medicines like toxins and poisons which would then be used in therapy or to stop functions

4.5 Homeostasis and Feedback Loops

Homeostasis achieved through constant internal environment Maintained with:

• Negative is reduces the effect, preventing anything from getting to high preventing extreme conditions. Ex. Is The use of an endocrine system to regulate blood pressure

• Positive Feedback Loops reinforce stimulate, this includes things such as:
  Child Birth, Lactation, Blood clotting, ripening fruit

4.6 Cell Cycle

M Phase- Includes
Interphase is about 90 of the cell
G Phase 1 is cell growth and the performance of functions. Some cells don’t want to have a cell cycle so end up going to a G 0 stage where they don’t undergo cell divide.
M Phase
mittosis includes prophase, metaphase, anaphase and telophase
Ctyokinenss includes cleaving material with a division of cytoplasm with cell organelles this is not a part of mitosis
Prophase:
Mitotic Spindle and sister Cromatides are form
Prometaphase:
Nuclear Envelope breaks down to allow mitotic access to DNA
Cromatides are formed as the protein structure assemble at the location where things are attached
Metaphase:
Alignment the chromosomes at metapahse and pull into the center of the cell.
Anaohase:
Seperattion of the protein at the center allows a movement toward opposite poles so that the microtubules move the poles
Telophase:
Chromosomes move to the opposite poles and then the nuclei reform and will return back into a chromtin
Ctyokinenss:
Division takes part and that then allow new cell in each side with a new cellular conent.

 Genome
 Prokaryotic is a single circle and no nucleus. Eukaryotic DNA is all chromosomes in the nucleus.

Cromaitn and Cromotide, somatic cells and genetics and other consideration
Tracking the different chromosome stages through Mitosis

4.7 Regulation of the Cell Cycle

* timing essential for nomr alg rowth and proper growth of tissues. 

G1 Check point if there enough space/ energy for the cells
G2 Check Point make sure all checked for Dna error
M check point make sure chromosomes have attached before Anaphase to have an equal distribution
Pahologies: If bad can cause cancer or trigger apopoposis (programmed cell death)
This can lead to therapeutic targets as the regulation can be used for drugs and medicine to help treat other causes

5.1/5.2 - Meiosis and Genetic Diversity

*Genetics: study of dna, heredity and the passing of traits (environmental factors matter)
Inherited from parent from sperm or egg (GAMETE)
homologous
chromosomes - pair of the ones you get from parents ( one from each) that can exchange segments during meiosis (crossing over, genetic recombination 4 unique gametes with dif combos)
A sexual reproduction is low variations and a sexual is fast
Meioiss
produces for genetically unique cells involved in sexual repro
Haploid
* Interphase
Replicated each chromosome is in chromatid form
*Meiosis 1 4 phases
Chromosomes form, then crossing over that results
in genetic code.
Then metaphase I indept Orient and line up
Then Anaphase is separation/ poles pulled
Then telosaphse
and cell separation that creates sets for

 *Meiosis 2 four phases

Creates chromes lined the same of mitosis at half the number. Separation of cell then occur.
Can cause cells will have nondisjunction (not properly separated)

5.3 - Mendelian Genetics

Mendilian gnetics the father of genetic experiment design to map traits and determine dominate and recesives genes.
7 Distinct traits
flaw poposite, stelem lengh, sheed shape seed colour and etc.

• Mended observation * F1 generations and dominate, 100 % *F2 gens had both in a 3:1 relationship the recessives then appeared
  Law of dominance when an organisms as 2 diff alleles
  alleles- that are sexually repordiced. One from mom one from dad
  modern exceptions
  Law of segregation during meiosis every trait passed. the sex is 1 ither sex
  determine if that it goes thru traits. they need traits but the parent does than traits
  * Dominant is in every generation autosomal or sex linked

5.4 - Non-Mendelian Genetics

not simple patterns that have diff traits and single genes. Instead there is diff patters
Incomplete Domananace, Co-dominance, Multiple alles all can effect the genotypes. The blood type is known as IA IB ii
albinos

6.0 - Discovering the DNA Structure

Qualifications:
Store Inform
Make Copies (Stable, replicable
Undergo change mutate! (variation)
historical discoveries
nucleic acids that are either DNA or RNA had sugar, phosphate nucleotides
What’s being stored and used, and what passes information to offspring?
proteinc = 20 diff amino acid to make different traits, or nucleic =4 nucleic to code for 20.
Transformatin:
Heat killed R strains and mixed with S stains which transformed stains into virile
s trains. And thus something in dead material transformed living
material . And then used bacteria to turn R material into S.

How does it help kill the mice
What about bacteria
Conclusion some transforming principle caused this and can effect blood flow!
What factor is at play
A Macleod then use enzyme to identify the dna
DNase (degrades
dna = no transformation
SO Dna it i

Hershey and chase also confirmed that DNA is genetic material
They used bacteriophages:
Then radiolabed 35S and 32 p is inside then found out DNA is inside. (and proteins are outside)
Charagafs discovered ratios are equal
Rosalia F and m Wilkins is the key to discovering helix is Photo/ray 51
Watson and cris discovered is at cold spring hrabour and revealed Double helix Dna

6.1 - DNA and RNA Structure

functions of DNA

• Heritable Info. That is passed down

• protein synthesis= Dna ->RNA->protie
  prokaryotic Vs eukaryotic Dna
  Euka: in nulcue and linearn
  Prco: nulce acid region circuar
  Plasmid replication dependent so if helpful gene is on the plasmid then they will transfer it
  So eca can easily be engineerd
  Restruciton ezyeme that can transfer and create. Gene and all bacteria can now be engineerd (insuling ex)

major point
DNA Vs RAN what is the diff?
DNA and RNA
Chargaraffds rule. A equals b

6.2 - DNA Replication

DNA replication ensure a continuity and errors
semicontseracative , conservative, dispersitve