Biochemistry Notes
Chemistry – study of what substances are made of and how they change and combine.
Each different kind of atom is a different element.
Examples of elements: C – Carbon H – Hydrogen
O – Oxygen N – Nitrogen
Two or more elements combine to make a compound.
Examples of compounds – H2O, CO2, HCl, NaCl
Compounds are classified into 2 groups:
1. Inorganic Compounds – come from nonliving substances (In = not Organic = living)
Ex: H2O is the universal solvent because of its bent molecular shape and polarity.
Water dissolves other polar compounds by pulling them apart like a magnet separates
metals.
Positive and
negative
ends like the
poles of a
magnet.
*70-80% of your body is water
2. Organic Compounds – come from living substances
Biochemistry – study of the chemistry of living organisms
All organic compounds will have the element carbon in them
Exception: CO2 is not organic (CO2 is not composed of living substances.)
Organic compounds are usually complex compounds with many atoms in their structure.
Ex: Glucose – C6H12O6
Four kinds of organic compounds:
1. Carbohydrates
2. Proteins
3. Lipids
4. Nucleic acids (to be covered more in depth later) – DNA and RNA
1
Carbohydrates
Read the paragraph on pages 45- 46 of your text to complete the following diagram.
• first and preferred energy
source of cells
Function • structural support in plants
• monosaccharides – (one
sugar)
Ex: glucose, fructose
• polysaccharides – (many
sugars)
Examples Ex: starch ***
Carbohydrates • plant starch
Ex: pasta, bread, rice
• cellulose – gives plant cells
rigidity and gives us fiber in
our diet
• Ratio – 1C:2H:1O
Ex: Glucose – C6H12O6
Compositon / • How are large
Structure macromolecules formed?
Smaller sugars combine to
make larger molecules.
Note: ***Polysaccharides are composed of monosaccharides bonded together
Polysaccharides must be first broken down to monosaccharides for cells to use as energy
Structural Formula of Monosaccharide:
2
Proteins
Read the paragraph on pages 47- 48 in your text to complete the following diagram
• control rate of reactions
• form bones and muscles
Function • transport substances in and
out of cells
• fights disease
• food examples from animals –
eggs, milk, meat
Examples • food examples from plants –
Proteins (not in the nuts, beans
reading)
• enzymes
• elements involved – C, N, H, O
• proteins are composed of –
amino acids
Structure • How many different amino
acids are there? 20
Structural Formula of Amino Acid:
3
Lipids
Read the paragraph on pages 46-47 in your text to complete the following diagram.
• store energy – provides
more energy per gram
Function than carbs
• part of cell membranes
and waterproof coverings
• fats
• oils
Lipids Examples • steroids
• waxes
• saturated – contains only
single bonds, solid at room
temp.
Diet info
• unsaturated – contains
(to be covered double bonds, liquid at
in class) room temp. (Better for your
diet.)
Structural Formula of Lipid:
4
Nucleic Acids
Read the paragraph on page 47 in your text to complete the following diagram
• store and transmit
Function genetic information
(parent to offspring)
Nucleic Acids
• DNA
Examples • RNA
5
Enzymes
Catalyst—substance that accelerates the rate of a chemical reaction
Ex: hydrogen peroxide being broken down into water and oxygen
H2O2 H2O + O2 add catalase for FASTER REACTION!
Enzyme – a kind of catalyst found only in living things
Enzymes are proteins
Enzymes change only the speed of the reaction
Enzymes are never used up in a reaction, so they can be used over and over
Enzymes are specific for the reaction they catalyze
Ex: Saltines and amylase
Starch Sugar
Enzymes allow digestion to occur faster; otherwise the hamburger you ate last week might
still be in your stomach!
By using enzymes to break chemical bonds in food molecules, organisms release energy for
life processes
6