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Organic Compounds

all living things fall into one of four classes of macromolecules: carbohydrates, lipids, proteins, and nucleic acids

macromolecules are polymers built from monomers

  • polymer: a long molecule consisting of many similar building blocks

  • these small building-block molecules are called monomers

  • three of the four classes of life’s organic molecules are polymers: carbohydrates, proteins, and nucleic acids

carbohydrates (CH2O) → ratio 1:2:1

  • carbohydrates serve as fuel and building material

  • they can be divided into three categories: monosaccharides, disaccharides, and polysaccharides

    • monosaccharides, simple sugars, are the simplest carbohydrates

      • glucose is the most common monosaccharide

      • all monosaccharides contain two functional groups: carbonyl (C=O) and a hydroxyl (OH)

      • monosaccharides serve as major fuel for cells and as raw material for building molecules

    • disaccharides are formed by joining two monosaccharides

      • sucrose, eg. table sugar

      • lactose, eg. sugar in milk

      • suffix is “-ose” for most sugars

    • carbohydrate macromolecules are polysaccharides, polymers composed of many sugar building blocks

      • made by linking many monosaccharides

        • eg. starch is a chain of many glucose molecules

      • have storage and structural roles

        • storage polysaccharides—starch and glycogen

        • structural polysaccharides—cellulose and chitin

storage polysaccharides

  • chitin is present in plants and consists entirely of glucose monomers

  • glycogen is present in animals and consists entirely of glucose monomers; it is how animals store sugars

    • humans and other vertebrates store glycogen mainly in liver and muscle cells

    • perennials: never die—need stored sugars (starch) to build stem and leaves in the Spring, then photosynthesize

structural polysaccharides

  • chitin is found in the exoskeleton of arthropods (a kind of animals)

    • also provides structural support for the cell walls of many fungi

  • cellulose is a major component of the tough wall of plant cells, also made of glucose monomers

    • humans can’t digest cellulose because we lack the enzymes to break the beta linkages between glucose molecules; we can break it down to some extent, but not at the molecular level

lipids

  • the most biologically important lipids are fats, oils, phospholipids, cholesterol, and steroids

  • lipids are non-polar parts of living things which contain long hydrocarbon tails

    • consist of a glycerol head and fatty acid tails

  • triglycerides consist of a glycerol head and three fatty acid tails

    • provide us with the most energy per gram of any substance

  • fats

    • saturated fats

      • animal fats like butter and grease

      • solidify at room temperature

      • carbons are “saturated” with hydrogen

    • unsaturated fats

      • plant oils like olive oil and peanut oil

      • remain liquid at room temperature

      • have hydrocarbon tails, long chains if C-H that are linked because the carbons are not saturated with hydrogen (C=C)

  • phospholipids

    • material of all cell membranes

    • phospholipid-glycerol, two fatty acids, and a phosphate group polar heads and non-polar tails

      • polar heads are hydrophilic (have an affinity to water)

      • non-polar tails are hydrophobic (repel water)

  • steroid: a lipid molecule in which the carbon solution forms four fused rings

  • cholesterol: an important steroid in animal cell membranes

    • can help membranes stay fluid by keeping the phospholipids from packing tightly together

    • used to make essential molecules such as hormones, fat-soluble vitamins, and bile acids

functions of lipids/fats

  1. energy storage (MAIN FUNCTION)

  2. humans and other mammals store their fat in adipose cells

  3. adipose tissue cushions vial organs and insulates the body

proteins

  • all enzymes are made of protein, but not all proteins are enzymes

  • protein: a polymer made of amino acid monomers

    • there are 20 amino acids; the human body can produce twelve, so we need eight from our diet

  • proteins have hundreds of functions, here are a few major ones:

    • work as enzymes

    • some are embedded in cell membranes that assist in the transport of substances

    • antibodies of the immune system are proteins

    • serve as hormones (chemical messengers)

    • muscle cells are made of protein and contract

    • structural proteins--collagen, ligaments, tendons

  • different proteins differ in number and order/arrangement of amino acids

    • amino acids are covalently bonded by peptide bonds

    • a polypeptide is a chain of amino acids with many peptide bonds

      • peptide bonds are connectors—if you have 40 amino acids, you will have 39 peptide bonds (one connecting each to the next)

    • a protein consists of one or more polypeptides

    • the sequence of amino acids determines the shape of a protein; its shape determines its function

  • denaturation: a process which changes the shape of a protein

    • temperature and pH level are the two main causes of denaturation

  • since the shape of the protein determines its function, the protein can no longer perform its function once it has been denatured

nucleic acids

  • nucleic acid: a polymer made of monomers called nucleotides

    • eg. DNA, RNA

  • nucleotide: a monomer consisting of sugar, a phosphate group, and a nitrogen-containing base

enzymes

  • activation energy: the amount of energy that must be absorbed for a chemical reaction to start

  • catalyst: a substance that decreases the activation energy needed to start a chemical reaction, therefore speeding up the rate of the reaction

  • enzyme: a catalyst made of protein which is present in living things

    • structure dictates function

    • changes in pH and temperature can affect shape and function

    • high fever/hypothermia denatures enzymes, causing functional problems

common characteristics of organic compounds

  • soluble in organic solvents, insoluble in water

  • high molecular weight

  • contain complex structures

  • properties are dependent on their functional groups

  • most consist of some combination of carbon, hydrogen, and oxygen

  • usually combustable in nature

Organic Compounds

all living things fall into one of four classes of macromolecules: carbohydrates, lipids, proteins, and nucleic acids

macromolecules are polymers built from monomers

  • polymer: a long molecule consisting of many similar building blocks

  • these small building-block molecules are called monomers

  • three of the four classes of life’s organic molecules are polymers: carbohydrates, proteins, and nucleic acids

carbohydrates (CH2O) → ratio 1:2:1

  • carbohydrates serve as fuel and building material

  • they can be divided into three categories: monosaccharides, disaccharides, and polysaccharides

    • monosaccharides, simple sugars, are the simplest carbohydrates

      • glucose is the most common monosaccharide

      • all monosaccharides contain two functional groups: carbonyl (C=O) and a hydroxyl (OH)

      • monosaccharides serve as major fuel for cells and as raw material for building molecules

    • disaccharides are formed by joining two monosaccharides

      • sucrose, eg. table sugar

      • lactose, eg. sugar in milk

      • suffix is “-ose” for most sugars

    • carbohydrate macromolecules are polysaccharides, polymers composed of many sugar building blocks

      • made by linking many monosaccharides

        • eg. starch is a chain of many glucose molecules

      • have storage and structural roles

        • storage polysaccharides—starch and glycogen

        • structural polysaccharides—cellulose and chitin

storage polysaccharides

  • chitin is present in plants and consists entirely of glucose monomers

  • glycogen is present in animals and consists entirely of glucose monomers; it is how animals store sugars

    • humans and other vertebrates store glycogen mainly in liver and muscle cells

    • perennials: never die—need stored sugars (starch) to build stem and leaves in the Spring, then photosynthesize

structural polysaccharides

  • chitin is found in the exoskeleton of arthropods (a kind of animals)

    • also provides structural support for the cell walls of many fungi

  • cellulose is a major component of the tough wall of plant cells, also made of glucose monomers

    • humans can’t digest cellulose because we lack the enzymes to break the beta linkages between glucose molecules; we can break it down to some extent, but not at the molecular level

lipids

  • the most biologically important lipids are fats, oils, phospholipids, cholesterol, and steroids

  • lipids are non-polar parts of living things which contain long hydrocarbon tails

    • consist of a glycerol head and fatty acid tails

  • triglycerides consist of a glycerol head and three fatty acid tails

    • provide us with the most energy per gram of any substance

  • fats

    • saturated fats

      • animal fats like butter and grease

      • solidify at room temperature

      • carbons are “saturated” with hydrogen

    • unsaturated fats

      • plant oils like olive oil and peanut oil

      • remain liquid at room temperature

      • have hydrocarbon tails, long chains if C-H that are linked because the carbons are not saturated with hydrogen (C=C)

  • phospholipids

    • material of all cell membranes

    • phospholipid-glycerol, two fatty acids, and a phosphate group polar heads and non-polar tails

      • polar heads are hydrophilic (have an affinity to water)

      • non-polar tails are hydrophobic (repel water)

  • steroid: a lipid molecule in which the carbon solution forms four fused rings

  • cholesterol: an important steroid in animal cell membranes

    • can help membranes stay fluid by keeping the phospholipids from packing tightly together

    • used to make essential molecules such as hormones, fat-soluble vitamins, and bile acids

functions of lipids/fats

  1. energy storage (MAIN FUNCTION)

  2. humans and other mammals store their fat in adipose cells

  3. adipose tissue cushions vial organs and insulates the body

proteins

  • all enzymes are made of protein, but not all proteins are enzymes

  • protein: a polymer made of amino acid monomers

    • there are 20 amino acids; the human body can produce twelve, so we need eight from our diet

  • proteins have hundreds of functions, here are a few major ones:

    • work as enzymes

    • some are embedded in cell membranes that assist in the transport of substances

    • antibodies of the immune system are proteins

    • serve as hormones (chemical messengers)

    • muscle cells are made of protein and contract

    • structural proteins--collagen, ligaments, tendons

  • different proteins differ in number and order/arrangement of amino acids

    • amino acids are covalently bonded by peptide bonds

    • a polypeptide is a chain of amino acids with many peptide bonds

      • peptide bonds are connectors—if you have 40 amino acids, you will have 39 peptide bonds (one connecting each to the next)

    • a protein consists of one or more polypeptides

    • the sequence of amino acids determines the shape of a protein; its shape determines its function

  • denaturation: a process which changes the shape of a protein

    • temperature and pH level are the two main causes of denaturation

  • since the shape of the protein determines its function, the protein can no longer perform its function once it has been denatured

nucleic acids

  • nucleic acid: a polymer made of monomers called nucleotides

    • eg. DNA, RNA

  • nucleotide: a monomer consisting of sugar, a phosphate group, and a nitrogen-containing base

enzymes

  • activation energy: the amount of energy that must be absorbed for a chemical reaction to start

  • catalyst: a substance that decreases the activation energy needed to start a chemical reaction, therefore speeding up the rate of the reaction

  • enzyme: a catalyst made of protein which is present in living things

    • structure dictates function

    • changes in pH and temperature can affect shape and function

    • high fever/hypothermia denatures enzymes, causing functional problems

common characteristics of organic compounds

  • soluble in organic solvents, insoluble in water

  • high molecular weight

  • contain complex structures

  • properties are dependent on their functional groups

  • most consist of some combination of carbon, hydrogen, and oxygen

  • usually combustable in nature