Section 6'4 The Building Blocks of Life

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Section 6.4 The Building Blocks of Life
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Todays Objectives

• Objective 1 Describe the role of carbon in
  living organisms
• Objective 2 Summarize the four major families
  of biological macromolecules
• Objective 3 Compare the functions of each
  group of macromolecules

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Organic Chemistry

• Organic chemistry
• The study of organic compounds- those compounds
  containing carbon
• Carbon is a compound of almost all biological
  molecules

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Organic Chemistry

• Carbon has four electrons in its outermost
  energy level, allowing it to form four other
  covalent bonds with other atoms
• These new compounds can be
• Straight chain molecules
• Branched molecule
• Ring molecules

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Macromolecules

• Macromolecules
• Large molecules that are formed by joining
  smaller organic molecules together
• These large molecules are also called polymers

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Macromolecules

• Polymers
• Molecules made from repeating units of identical
  or nearly identical compounds called monomers
  that are linked together by a series of covalent
  bonds

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The Big Four

• Although there is almost an endless variety of
  living things on Earth, most things are made of
  four kinds of chemicals
• Carbohydrates
• Lipids
• Proteins
• Nucleic Acids

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1 Carbohydrates

• Many carbohydrates provide a usable energy source
  and provide shape to organisms
• Carbos are a group of
• chemicals that include
• sugars, starches, and
• cellulose
• Athletes will carbo-load

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Carbohydrates

• Simple sugars are a form of carbos, and are the
  easiest chemicals for your body to break down
• This is why you get a sugar buzz

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Carbohydrates

• Sugars commonly come in two forms
• Monosaccharides (single sugars)
• Disaccharides (double sugars)
• When linked together, you get a more complex
  carbohydrate called a polysaccharide

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• Monosaccharide
• Simple Sugars
• Disaccharide .
• Complex Carbo
• Polysaccharide

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Examples of Polysaccharides

• The starch stored in
• potatoes (Most plants
• store energy in the form
• of starch)
• Stored energy in our bodies called glycogen,
  which is formed in the muscles and liver

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2 Lipids

• Carbos are used for some energy storage
• When energy needs
• to be stored for an
• even longer period
• of time, carbos are
• converted into fat
• (a kind of lipid)

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Lipids

• Lipids are a group of chemicals that include
  fats, oils, waxes, phospholipids, and steroids
• Fats and oils provide long-term energy storage

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Lipids

• Fats also act as insulation

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Lipids

• Waxes repel water

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Lipids

• Phospholipids form the membrane, or protective
  covering, that covers cells
• Phospholipids help
• control substances
• entering or leaving
• the cell

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Lipids

• Steroids serve as structural and control
  functions in your body

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3 Proteins

• Proteins are large, complex molecules composed of
  many smaller molecules called amino acids
• More than half of the dry weight of your body is
  protein

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Proteins

• Organisms use only 20 amino acids to make
  proteins
• Different combinations of amino acids produce
  different proteins
• Just like a recipe for food!

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Proteins

• One very important group of proteins are called
  enzymes
• Enzymes help control chemical reactions

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• Enzymes are involved in digesting food, releasing
  energy during cellular respiration, and building
  up proteins

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4 Nucleic Acids

• Nucleic Acids are large, complex molecules that
  contain hereditary, or genetic information
• These molecules control inherited characteristics

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Nucleic Acids

• Two kinds of nucleic Acids exist
• Deoxyribonucleic acid (DNA)
• Ribonucleic acid (RNA)

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Nucleic Acids

• DNA carries instructions that controls activities
  of a cell (like a blueprint)
• RNA uses those instructions to make proteins