Biology

• LEVELS OF BIOLOGICAL ORGANIZATION

  1. individual
  2. population - all individuals of the same species in an area
  3. community - all populations in an area
  4. ecosystem - all communities and their environment
  5. biosphere - all ecosystems on Earth
• MODERN CELL THEORY

  1. The cell is the most basic unit of life
  2. All organisms are made up of cells
  3. All cells arise from other cells.
  4. All cells have similar biomolecules and biochemical reactions
  5. All cells contain genetic material which is passed on from one cell to another
  6. All chemical and physiological processes in the body happen in the cell
• no true nucleus, no membrane-bound organelles, mostly unicellular, (Archaea, Bacteria)

  Prokaryotic
• has true nucleus, has membrane-bound organelles, unicellular, multicellular, (Animalia, Fungi, Plantae, Protista)

  Eukaryotic
• BIOMOLECULES

  • Carbohydrates - building blocks: monosaccharides (starch, cellulose)
  • Proteins - building blocks: amino acids (enzymes, hormones)
  • Lipids - building blocks: fatty acids, glycerol (steroids, fats)
  • Nucleic Acids - building blocks: nucleotides ( DNA, RNA)
• DNA

  • sugar backbone - deoxyribose
  • no. of strands - double
  • base pairing - Adenine‐Thymine(A‐T) Guanine‐Cytosine(G‐C)
• RNA

  • sugar backbone - ribose
  • no. of strands - single
  • base pairing - Adenine‐Uracil(A‐U) Guanine‐Cytosine(G‐C)
• Organelles present only in prokaryotes

  • nucleoid region
  • capsule
  • plasmid - extra circular DNA
  • pilli
• ORGANELLE FUNCTIONS

  • cell membrane - cell communication and transport
  • genetic material - storage of genetic information
  • ribosomes - protein synthesis
  • nucleus - command center
  • Golgi apparatus - transportation of proteins and other cellular components
  • endoplasmic reticulum - protein synthesis and lipid production
  • mitochondria - ATP synthesis
  • lysosome - cellular digestion
  • chloroplast - photosynthesis
  • vacuole - storage of food and other cellular comonents
  • cell wall - structural support, protection, controls cell transportation
  • centrioles - production of spindle fibers during cell division
• Organelles present in both prokaryotes and eukaryotes

  • ribosomes
  • cytoplasm
  • cell membrane
  • genetic material
• equational division; 2 daughter cells; produces somatic or body cells; for growth and repaor

  Mitosis
• reductional division; 4 daughter cells; produces sex cells or gametes; for reproduction

  Meiosis
• chemical reavction in the body's cells that change food into energy

  Metabolism
• catabolism - breaking down

  anabolism - building-up
• PHOTOSYNTHESIS

  CO2+H2O -> C6H12O6+O2
• Steps in photosynthesis

  1. Light‐dependent reactions -conversion of light energy and water to chemical energy and oxygen
  2. Light‐independent reactions/ Calvin Cycle - formation of carbohydrate molecules from carbon dioxide using the chemical energy produced from light-depent reactions
• anaerobic respiration; replaces Krebs Cycle and electron-transport chain if oxygen is absent


  fermentation
• Lactic acid fermentation - converts glucose into lactic acid (C3H6O3)

  Ethanol fermentation - converts glucose into ethyl alcohol (C2H5OH)
• Steps in Respiration: GOCO

  1. Glycolysis - conversion of glucose to pyruvate
  2. Oxidation of pyruvate - conversion of pyruvate to acetyl CoA
  3. Citric Acid/TCA/Krebs Cycle - a 10‐step cycle that produces oxaloacetate from acetyl CoA
  4. Oxidative Phosphorylation - consists of electron transport chain and chemiosmosis; synthesis of ATPs using ATP synthase
• gene forms for a certain trait

  alleles
• having two of the same allele (e.g. RR or rr);purebred

  homozygouz
• having two different alleles for a certain trait (e.g. Rr); half bred

  heterozygous
• hidden or masked gene

  recessive
• expressed gene

  dominant
• organisms's physical characteristics

  phenotype
• an organism's actual genetic composition

  genotype
• THE DNA DOUBLE HELIX STRUCTURE

  • sugar-phosphate backbone
  • base
  • hydrogen bonds
  • polynucleotide chains nitrogen base pairings:
  • Cytosine-Guanine Adenine-Thymine
• CENTRAL DOGMA OF MOLECULAR GENETICS

  1. DNA-replication
  2. transcription
  3. RNA
  4. translation
  5. protein
• the DNA double chain "unzips" and a new completely strand is formed for each unzipped strand, creating two complete double chains


  replication
• RNA for protein synthesis is created from DNA; instead of adenine-thymine, the base is now adenine-uracil


  transcription
• the messenger RNA produced from transcription will be used as a template for the synthesis of amino acids; three bases code for amino acid


  translation
• each gene directs the synthesis of a protein enzyme thqt controls a chemical reaction of the cell; the chemical reactions, in turn, determine the phenotype of the organism

  One Gene-One Enzyme Hypothesis
• CLASSIFICATION OF ORGANISMS

  • Domain archaea -prokaryotic, Kingdom Archaebacteria, extremophiles(love extreme environments)
  • Domain bacteria - prokaryotic, Kingdom Eubacteria, true bacteria
  • Domain Eukarya - eukaryotic, Kingdoms Animalia, Fungi, Protista, Plantae, diverse group
• not photosynthetic, most has cell wall, is uni-cellular; example: Halobacterium

  Archaebacteria
• some are photosynthetic(cyanobacteria), most has cell wall, is unicellular; examples: Lactobacillus, Clostridium

  Eubacteria
• some are photosynthetic(Algae, Euglena), some has cell wall(cellulose), most are unicellular; Examples: Amoeba, Paramecium, algae, slime molds, water molds

  Protista
• not photosynthetic, has cell wall, many are unicellular; example(yeasts, mushrooms, most molds)

  Fungi
• photosynthetic, has cell wall, not unicellular, examples(mosses, fern, conifers, grasses

  Plantae
• not photosynthetic, has no cell wall, is not unicellular, examples(sponges, corals, sea urchins)

  Animalia
• PLANTS

  no xylem and phloem; no roots, stems or leaves; reproduce through spores; e.g. mosses, liverworts, hornworts

  Non-vascular plants