Chapter 2.3: Chemistry of Cells

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Chapter 2.3 Chemistry of Cells

• Biochemistry

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Organic Compounds

• Organic molecules are molecules that contain
  Carbon atoms bonded usually to Hydrogen, Oxygen
  or other Carbon atoms.
• The four most important organic compounds found
  in living things are
• - Carbohydrates
• - Lipids
• - Proteins
• - Nucleic Acids

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Carbohydrates (The dreaded carb!)

• Made of Carbon, Hydrogen and Oxygen.
• For every Carbon atom there is an Oxygen and two
  Hydrogens. 1 2 1
• Carbohydrates are a huge source of energy.
• Carbs are made of single sugar molecules called
  monosaccharides.
• An example of a monosaccharide is glucose C6H12O6
  Notice the ratio!

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Carbohydrates cont.

• Does this look familiar?
• This is a monosaccharide called glucose.
• A single sugar molecule can easily be pieced
  together with another sugar to make a
  disaccharide.
• When this is done 1 molecule of water is
  released.

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Forming a disaccharide

• Notice that when you remove a water molecule the
  two molecules bond together to form a much larger
  molecule.
• What do you think will happen if you throw in a
  water molecule?

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Forming a carbohydrate

• If you take more than two glucose molecules and
  bond them together you form a polysaccharide.
• Each one of the little blue hexagons a glucose
  molecule

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Examples of Carbohydrates

• What is the carbohydrate that is stored in
  plants?
• Hint
• Starch
• The carbohydrate that is found in animals is
  called glycogen.
• These polysacharides store a lot of energy in the
  form of sugar.
• Sugar turns into fat.
• Hence the carb diet
• When you break down a polysaccharide not only do
  you lose water you release energy.

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Lipids

• A Lipid is a non-polar organic molecule that is
  one of the principal structural materials of
  living cells.
• A lipid is not soluble in water Why?
• Lipids are oily or greasy in texture.
• Examples of lipids are fats, phospholipids,
  steroids and wax.
• Some lipids can be pieced together to form larger
  molecules.

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Phospholipids

• Phospholipids, like fat, and cholesterol are made
  of two distinct parts.
• - Glycerol
• (Polar Head)
• - Fatty Acid tails (Non-polar tail)

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Phospholipids Cont.

• If you take a bunch of phospholipids and put them
  in water what do you think might happen?
• Because of the properties of phospholipids, when
  in the presence of water a group of them will
  form what is called a phospholipid bi-layer.
• This is what makes up the cell membrane.

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FAT

• Fat a lipid in an organism that stores ENERGY.
• Fat is also made of glycerol and fatty acids.
• Glycerol is an alcohol
• Fatty acids are a bunch of Carbons bonded to
  Hydrogens

Do you notice any similarity between a fat and a
phospholipid?
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Different types of fat

• There are two different types of fat that store
  energy in the body.
• Saturated fat The Carbons in the fatty acid are
  all bonded to two Hydrogens, except for the last
  which is bonded to three. This forms a straight
  molecule.
• Unsaturated fat Some Carbons are only bonded to
  one Hydrogen, making a double bond and causing a
  kink in the chain.

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Saturated and Unsaturated Fat

• Which fat is the bad fat? Why?

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Protein

• Proteins are made of a chain of amino acids
  linked together.
• Great! Whats an amino acid?
• Amino Acid The building blocks of a protein.
  There are 20 different amino acids, each with a
  different chemical structure.
• All amino acids are made of Carbon, Hydrogen,
  Oxygen and Nitrogen.
• Some of the 20 amino acids are made of sulfur.

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Proteins cont.

• Each amino acid has a similar chemical structure
  but different functional groups.
• Another type of functional group is the R
  group. This is what gives us our 20 different
  amino acids

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Proteins cont.

• Some amino acids are polar
• Some amino acids are electrically charged.
• These give proteins a very distinct shape.

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Nucleic Acids an intro

• Nucleic Acid a long chain of nucleotides.
• Once again Great! Whats a nucleotide?
• Nucleotide part of a nucleic acid that has
  three parts.
• 1. Sugar
• 2. Nitrogen base
• 3. Phosphate group

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Nucleotides
Nucleotides are put together to make a Nucleic
Acid like so
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Nucleic Acid
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Nucleic Acids cont.

• There are two types of nucleic Acids
• - Deoxyribonucleic Acid (DNA)
• Double stranded
• - Ribonucleic Acid (RNA)
• Single stranded

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ATP

• ATP Adenosine tri-phosphate (ENERGY)
• A single nucleotide with two extra phosphates.
• Main energy resource for cells.
• Energy from carbs and fat are stored temporarily
  as ATP.
• When ATP is broken down it turns into ADP and
  releases energy.

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ATP
When one of the phosphate groups are broken off
Energy is released
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ATP cycle