Biology EOC Highlight Review

Biology EOC Highlight Review

Organic Compounds

• All living things are composed of organic compounds.

• Organic compounds contain the element Carbon.

• Primary types of organic compounds:

  • Carbohydrates

  • Proteins

  • Lipids

  • Nucleic Acids

Carbohydrates

• Monomer: Monosaccharide

• Primary Functions:

  • Energy source

  • Structural component

• Tests:

  • 5Glucose: test with Benedict's solution

  • Starch: test with Iodine

• Examples of carbohydrates:

  • Cellulose

  • Glycogen

  • Starch

Lipids

• Composed of Fatty acids and Glycerol.

• Primary Functions:

  • Energy storage

  • Insulation

• Tests: Conduct a Brown paper test.

• Examples: Fats and Steroids.

• Comparison: Lipids vs. Water.

Nucleic Acids

• Monomer: Nucleotide

• Primary Function: Carries genetic information.

• Structure of Nucleotide:

  • Phosphate group

  • Sugar (Deoxyribose or Ribose)

  • Nitrogenous base (e.g., A, T, C, G)

• Examples: DNA and RNA.

Proteins

• Monomer: Amino acids

• Primary Functions:

  • Building and repairing cells

  • Communication between cells

  • Transport within the organism

  • Regulatory functions

• Tests: Use Biuret's reagent.

• Examples: Enzymes, Hemoglobin.

Enzymes

• Definition: Catalysts in living organisms.

• Features:

  • Specific to a particular substrate.

  • Reusable after catalyzing a reaction.

  • Sensitive to temperature and pH levels.

Cells

Prokaryotes

• Characteristics:

  • Simple structure with no membrane-bound organelles.

  • Examples: Bacteria only.

  • Contain one circular chromosome.

  • Components include:

  • Chromosome

  • Ribosomes

  • Plasma membrane

Eukaryotes

• Characteristics:

  • Possess membrane-bound organelles.

  • Include both plants and animals.

  • Feature a true nucleus containing chromosomes.

Cell Structures

Nucleus

• Described as the "Control Center" of the cell.

• Contains chromosomes.

Mitochondria

• Singular: Mitochondrion.

• Described as the "Powerhouse" of the cell.

• Function: Produces energy in the form of ATP.

• Main site of aerobic respiration.

Chloroplast

• Function: Site of photosynthesis.

• Present in plant cells only.

• Contains the pigment chlorophyll.

Vacuole

• Function: Storage of excess materials.

• In plant cells, usually contains one large vacuole.

Ribosomes

• Function: Site of protein synthesis.

• Found in both prokaryotes and eukaryotes.

Plasma Membrane (Cell Membrane)

• Function: Surrounds the cell, regulates the entry and exit of substances.

• Role: Helps maintain homeostasis.

• Composed of phospholipids with embedded proteins.

Cell Wall

• Present in plant cells only.

• Function: Provides support and protection for the cell.

• Composed of cellulose.

Eukaryotic Cells

• Plant Cells:

  • Features: Cell wall, large central vacuole, chloroplasts.

• Animal Cells:

  • Features: Lack cell walls, smaller vacuoles, no chloroplasts.

Cell Organization

• Levels of Organization:

  • Atoms → Molecules → Cells → Tissues → Organs → Organ Systems → Organisms.

Cell Specialization

• Definition: Cells develop to perform different functions.

• Regulation: Controlled by genes.

Cell to Cell Communication

• Mechanism: Chemical signals (hormones) sent between cells.

• Receptor Proteins: Located on plasma membrane, receive signals.

Transport Mechanisms

Diffusion

• Definition: Passive transport, no energy needed.

• Process: Solutes move from areas of high concentration to low concentration.

Osmosis

• Definition: Diffusion of water, also a passive transport mechanism.

• Types of Solutions:

  • Hypotonic Solution: Higher water, less solute.

  • Hypertonic Solution: Less water, more solute.

• Utilizes a selectively permeable membrane.

Active Transport

• Definition: Movement of particles against the concentration gradient, requiring energy (ATP).

• Process: Moves from low concentration to high concentration.

ATP (Adenosine Triphosphate)

• Definition: The energy-storing molecule in cells.

• Can be used for quick energy by the cell.

• Energy is stored in the phosphate bonds.

Photosynthesis

• Process: Utilizes water and carbon dioxide to produce glucose and oxygen.

• Chemical Reaction: $H_2O + CO_2 <br>ightarrow C_6H_{12}O_6 + O_2$.

• Occurs in the chloroplasts.

Aerobic Respiration

• Function: Releases energy (ATP) for cellular use.

• Chemical Reaction: $C_6H_{12}O_6 + O_2 <br>ightarrow H_2O + CO_2$.

• Occurs in the mitochondria.

Anaerobic Respiration (Fermentation)

• Definition: Does not require oxygen.

• Function: Used to release energy, but less efficient than aerobic respiration (produces less ATP).

• Products: Include CO2 and lactic acid or alcohol.

• Types: Alcoholic Fermentation and Lactic Acid Fermentation.

Autotroph vs. Heterotroph

• Autotrophs: Organisms that obtain energy from the environment (e.g., photosynthesis or chemosynthesis), referred to as "producers".

• Heterotrophs: Organisms that obtain energy from other living things, referred to as "consumers".

DNA / RNA

• Both carry genetic information.

• Composed of chains of nucleotides.

• Nucleotide Structure:

  • Sugar (Deoxyribose in DNA, Ribose in RNA)

  • Phosphate group

  • Nitrogenous base (A, T, C, G for DNA; A, U, C, G for RNA).

DNA

• Structure: Double stranded, forms a "double helix".

• Base Pairs: A pairs with T, and G pairs with C.

• Location: Found in the nucleus.

RNA

• Structure: Single stranded.

• Base Pairs: A pairs with U, and G pairs with C.

• Function: Transcription and translation of genetic information.

Base Pair Rule

• In DNA, Adenine always pairs with Thymine, and Guanine always pairs with Cytosine.

Replication

• Definition: The process of making an identical strand of DNA.

• Described as semi-conservative.

Central Dogma

• Flow of genetic information:

  • $DNA <br>ightarrow RNA <br>ightarrow ext{Protein} <br>ightarrow ext{Trait}$.

Transcription

• Processes: Conversion of DNA to mRNA.

• Location: Occurs in the nucleus.

• Produces a complementary mRNA strand from a segment of DNA.

Translation

• Definition: Connects amino acids in the correct order to form a protein.

• Location: Occurs in the cytoplasm, within ribosomes.

• Components of translation:

  • A - Amino Acid

  • B - tRNA

  • C - Anticodon

  • D - Codon

  • E - mRNA

  • F - Ribosome

  • G - Polypeptide.

Codon

• Definition: A sequence of three mRNA nucleotides that codes for an amino acid.

• Each amino acid is represented by a specific codon.

Mutations

• Definition: Change in the DNA code that may affect the protein produced.

• Note: Mutations are not always harmful (e.g., Sickle Cell Mutation).

Mitosis

• Definition: A type of cell division that produces two identical diploid daughter cells.

• Purpose: To grow and repair body cells.

Cancer

• Definition: Error in normal cell growth leading to uncontrolled cell proliferation.

• Influenced by environmental and genetic variables.

Meiosis

• Definition: Cell division that produces four different haploid daughter cells (gametes).

• Purpose: Forms sex cells for reproduction.

Crossing Over

• Explanation: Homologous chromosomes exchange segments of DNA during meiosis.

• Results in increased genetic variation in gametes.

Nondisjunction

• Definition: Failure of homologous chromosomes to separate properly during meiosis.

• Consequences: Can lead to genetic disorders such as Down Syndrome, Turner Syndrome, and Klinefelter Syndrome.

Asexual vs. Sexual Reproduction

• Asexual Reproduction:

  • Involves one parent.

  • Produces identical offspring.

  • Variation occurs only through mutations.

  • Examples: Budding, fragmentation, fission.

• Sexual Reproduction:

  • Involves two parents.

  • Produces offspring genetically different from parents.

  • More variation due to genetic recombination.

  • Fertilization involves the fusion of gametes.

Inheritance

• Traits: Specific characteristics inherited from parents.

• Genes: Factors that determine traits.

• Alleles: Different forms of a gene.

Dominant/Recessive Alleles

• Dominant alleles: Expressed if present.

• Recessive alleles: Hidden if a dominant allele is present.

• Example alleles for flower color:

  • Purple flowers allele vs white flowers allele.

Genotype vs. Phenotype

• Genotype: The actual allele composition (e.g., BB, Bb, bb).

  • Homozygous: Both alleles are the same (e.g., BB or bb).

  • Heterozygous: Both alleles are different (e.g., Bb).

• Phenotype: The observable physical expression of a trait (e.g., brown eyes, height).

Incomplete Dominance

• Definition: Heterozygote exhibits a blending of dominant and recessive phenotypes.

• Representation: States with superscripts to reflect alleles.

Codominance

• Definition: Heterozygote expresses both dominant and recessive traits simultaneously.

• Example: Roan animals where both coat colors appear.

Polygenic Traits

• Definition: Traits influenced by multiple genes.

• Example: Skin color which relates to several gene interactions.

Multiple Alleles

• More than two alleles exist for a trait; however, individuals can only inherit two.

• Example: Blood Type System.

  • Type A: $IAIA$ or $IAi$

  • Type B: $IBIB$ or $IBi$

  • Type AB: $IAIB$

  • Type O: $ii$.

Sex-Linked Traits

• Sex Chromosomes: Female - XX, Male - XY.

• Definition: Traits associated with genes located on the X chromosome.

• Examples: Hemophilia, red-green colorblindness.

Test Cross

• Definition: Used to determine the genotype of an unknown dominant individual.

• Method: Crosses with a homozygous recessive individual.

Pedigree

• Description: A diagram akin to a family tree showing the pattern of inheritance for a specific trait.

Karyotype

• Definition: A visual representation of an individual's chromosomes.

• Used to detect chromosomal disorders such as Down Syndrome, Klinefelter's Syndrome, and Turner Syndrome.

Origin of Life

• Abiotic Earth: Lacked oxygen.

• Early Organisms: Anaerobic prokaryotes.

• Experiment: Miller and Urey recreated the abiotic atmosphere.

Endosymbiotic Theory

• Explanation: Eukaryotic cells evolved from prokaryotic cells.

• Historical Significance: Early prokaryotes engulfed other prokaryotes, forming symbiotic relationships.

• Evidence: Mitochondria and chloroplasts contain prokaryote-type DNA.

Abiogenesis vs. Biogenesis

• Abiogenesis: Old theory of living organisms originating from non-living matter, disproven by experiments.

• Biogenesis: Theory that living organisms arise from pre-existing living matter.

  • Experiments by Redi and Pasteur established this fact.