bio 3

• Review: Which of the following is NOT a function of proteins?
• Nucleic acids


  • Biological polymers whose monomers are called nucleotides
  • Store & transmit heritable information (Blueprints)
  • 2 types: Deoxyribonucleic acid (DNA) and Ribonucleic acid (RNA)

  
• Deoxyribonucleic acid (DNA)

  • The blueprint or instruction manual of the cell
  • Gene: The basic physical and functional unit of heredity, made up of DNA, acting as instructions to make proteins

  
• Central Dogma

  DNA-RNA-Protein
• Deoxyribonucleic Acid (DNA)


  • Directs its own synthesis through the process of replication
  • Directs the synthesis of RNA through the process of transcription

  
• Nucleotide


  Monomer composed of a phosphate group, pentose sugar and a nitrogenous base

  
• Nucleotide: Pentose Sugar


  Deoxyribose in DNA, Ribose in RNA

  
• Nucleotide: Nitrogenous Base


  • Can be either pyrimidines or purines
  • Uracil is used in RNA instead of thymine

  
• How Nucleotides (monomers) form Nucleic Acids (polymers)


  1. Connect pentose sugar of one nucleotide to the phosphate of another nucleotide

  2. Linkage is called a phosphodiester bond and is formed by dehydration synthesis

  3. Leads to the formation of a sugar phosphate backbone

  
• Double helix


  • DNA consists of 2 strands (double stranded)
  • RNA is single stranded
  • Wrapped into a double helix
  • The nitrogenous bases are inside the helix

  
• DNA Complementarity


  • A hydrogen bonds with T
  • G hydrogen bonds with C
  • Each strand works as a template (model) during replication
  • During replication, the H-bonds break & new H-bonds form

  
• Discovery of the Double Helix
• What type of macromolecule is depicted in the image below?
• Adenosine triphosphate (ATP)


  • ATP (adenosine (adenine + ribose) triphosphate (3x phosphate))
  • Energy currency of the cell
  • Stores Energy for: Cellular work, Transportation, Chemical reactions

  
• ATP consists of 3 components

  • 1. A nitrogenous base called adenine
  • 2. A 5-carbon sugar called ribose
  • 3. Three phosphate groups which are negatively charged

  
• What's so special about ATP?

  • Energy currency of the cell
  • Breaking down ATP releases energy
  • The process is called hydrolysis because water is involved in breaking the bonds
• ATP is a renewable resource in the cell


  • Breaking ATP releases energy that can be used to power cell machinery
  • ATP can be rebuilt when a chemical reaction in the cell releases energy
  • When ATP breaks down, it releases a phosphate group, called inorganic phosphate (Pi)
  • Adenosine triphosphate (ATP) loses a phosphate to become adenosine diphosphate (ADP)
• Processes that release energy

  • Catabolism: The process of breaking larger molecules into smaller molecules
  • Catabolic processes are exergonic
• Processes that require energy

  • Anabolism: The process of building larger molecules from smaller molecules
  • Anabolic processes are endergonic
• The ATP cycle
• Big Question: Where does all of the energy ultimately come from that powers the chemical reactions for life on Earth?
• Why do we need to eat?

  Absorbing food molecules: Supplies energy to the body, Supplies building blocks for macromolecules, Supplies energy reserves for future use
• Nutrients


  • Chemical substance in food that body cells use for growth, maintenance and repair
  • 6 types: Carbohydrates, Lipids, Proteins, Water, Minerals, Vitamins
• Nutrition: Carbohydrates


  • Rapid energy source for the body
  • Glucose is the preferred source of energy for ATP synthesis
  • Some carbohydrates are non-digestible (dietary fibers like cellulose)
  • Insoluble fiber: laxative effect and may reduce the risk of colon cancer
  • Soluble fiber: combines with cholesterol in food to prevent cholesterol absorption
• Nutrition: Fats


  • Highest energy content (twice as much as carbohydrates)
  • Can be stored under skin and around organs for later use
  • Saturated fats and cholesterol: Important nutrients but should be controlled because they contribute to plaques which clog arteries
  • Unsaturated fats (mono and poly): Not associated with disease, Omega-3 and omega-6 fatty acids are essential
• Nutrition: Proteins


  • Rarely used as a source of energy
  • Source of amino acids (including essential ones)
  • Vegetarians need to make sure they are getting all amino acids
  • Animal sources: milk and dairy products, meat, fish, eggs
  • Plant sources: seeds, beans, chickpeas, peas, nuts, peanuts
• The image depicted below represents a monomer of what type of biomolecule polymer?

  
• Which of the following molecules is used as a form of energy storage in animals?
• The process of building a molecule of glucose from smaller molecules is best described as:
• Water


  • Acts as a medium for biochemicals (solvent)
  • Participates in many biochemical reactions
  • Temperature regulation
  • Lubricant
• Minerals


  • Inorganic nutrients
  • Calcium: Most abundant, needed for bones/teeth, muscle contraction, blood clotting
  • Phosphorus: Needed for bones, component of macromolecules
  • Sodium: Needed for fluid balance, nerve/muscle signal conduction, excessive intake linked to high blood pressure
  • Iron: Component of blood (hemoglobin)
• Vitamins


  • Organic nutrients required in small amounts to maintain growth and normal metabolism
  • Do not provide energy or serve as building blocks for macromolecules
  • Fat soluble: A, E, D, K, absorbed with fatty food, excess stored in liver
  • Water soluble: B vitamins and vitamin C, excess excreted in urine
  • Help enzymes function, some have antioxidant properties, needed for bone health, blood health