Download Proteins

Human Systems!
General Learning Outcomes
Explain how the human digestive and respiratory systems
exchange energy and matter with the environment
Explain the role of the circulatory and defence systems
Explain the role of the excretory system
Explain the role of the motor system
Today’s Learning Outcomes
Describe carbohydrates, lipids, nucleic acids
and proteins and their enzymes
Explain how enzymes work
Carbohydrates
Carbohydrates are often described as energy nutrients
They make up the largest component of most diets
Can be found in potatoes, bread, rice, corn, etc.
These need to be eaten in smaller quantities due to the fact
that they are stored as fat in your body
Carbohydrates
Humans cannot make carbohydrates so we must get them
from our food sources
Plants are our source of carbohydrates - they make them
through photosynthesis
Carbohydrates are sugars!
Carbohydrates
Carbs can be single sugar units or polymers which are
composed of three or more subunits
Single sugar units, like glucose, have a 1:2:1 ratio of
carbon, hydrogen and oxygen
Carbs can also be classified according to the number of
sugar units they contain
Carbohydrates
Monosaccharides are the simplest sugars containing a
single sugar unit
Examples: glucose, galactose, fructose
Carbohydrates
Disaccharides are the combination of two monosaccharides
examples: lactose, maltose, sucrose
Polysaccharides are the combination of many
monosaccharide molecules
examples: starch, glycogen, cellulose
Lipids
One of the most important functions of lipids is to store
energy
Another important function is to form cell membranes
Lipids
Three groups:
1. Triglycerides
a. Saturated (butter)
b. Unsaturated (oil)
2. Phospholipids
a. Cell membranes
3. Waxes
Proteins
Not primarily energy compounds
Used to form structural parts of a cell
Composed of amino acids
Protein in your diet is important to help your body obtain
certain amino acids (there are 8 the body can’t make)
Proteins
Primary structure of a protein is the chain of amino acids
Proteins
Secondary structure is the coiling and folding creating
alpha helices and beta pleated sheet structures
Proteins
Tertiary structure consists of further folding of the
secondary structures
Proteins
Quaternary structures are the clustering of two or more
polypeptides. Hemoglobin is a quaternary protein
Proteins
Denaturation is when the bonds of the protein are broken
causing it to uncoil or form a new shape. This is caused by
heat, pH, or radiation. This change is not permanent
Coagulation is a permanent change in the structure.
Example is a boiled egg
Enzymes
Enzymes are very important molecules
They are used most of the time to catalyze reactions
(increase the speed or helping them to start in the first
place)
Enzymes work with specific substrates. They are specific to
each other (lock and key analogy)
Enzymes
Enzymes have the suffix -ase
Examples:
carbohydrases breakdown carbohydrates
proteases breakdown proteins
lipases breakdown lipids
Enzymes
Enzymes have a specific active site where the substrate
can bind to it
Enzymes
Factors that affect enzyme reactions:
1. pH
a. Each enzyme has a pH they work best in
2. Substrate Molecule Concentration
a. THe more substrates, the more reactions
3. Temperature
a. Each enzyme has a temperature they work best in
4. Competitive Inhibition
a. A molecule with a shape similar to the substrate
competes for access to the active site
Enzymes
Enzymes are regulated through feedback systems