Fructose and glucose are monosaccharides. They both have the same formula which is C6H1206 but the placement of the carbon atoms is different. Glucose is classified as aldehyde which is a carbonyl group with at least one hydrogen attached to it but fructose is classified as a ketone which is contains a carbonyl group with t
wo hydrocarbon groups attached to it.
Both carbohydrates and lipids are built of C,H,O. How can you tell them apart ?
They both have different amount of molecules and different ratios. Carbohydrate has C:O 1:1 ratio and lipids C:O ratio is really high in Carbon. The chemical structures are also different. For instance, fatty acids have long chain with a -COOH on one end and a -CH3 at the other. Carbohydrates general formula is CH2O. Carbohydrates have a ring shape but lipids don't.
Cellulose and starch are both made of repeating units of glucose. What is different about their structure that gives them such different chemical properties ?
They are both polysaccharides and used for storage and structure. They are both made of glucose. In starch, all the glucose molecules oriented in the same direction. But in cellulose, each glucose unit is rotated 180 degrees around the axis of the polymer backbone chain. Our body has enzymes to digest starch but not the cellulose. Cellulose is a lot stronger than starch.
Lipids don't have a common chemical structure. Why are they grouped together into the same macromolecule class?
They are called lipids because they share one important trait which is they are insoluble in water or in other polar solvents but are soluble in nonpolar substances like ether. It means that they are all hydrophobic.
Identify and describe the four levels of protein structure.
The primary structure is basically the order of amino acids. The secondary structure is the shape results from hydrogen bonding between the amino and carboxyl groups of adjacent amino acids. If the bonding produces a spiral, it is called alpha helix, if it looks like the pleats on a skirt it's then called beta pleated sheet. Tertiary structure is the third level of protein structure. Hydrogen bonding, ionic bonding, the hydrophobic bonds and the formation of disulfide bond contribute to the tertiary structure. Quaternary structure describes a protein that is assembled from two or more separated peptide chains.
How do saturated fats differ from unsaturated fats both in structure and in behavior?
The saturated fats have no double bonds while unsaturated fats have one or more C=C bonds. So unsaturated fats can accept more H. Saturated fats are found in animal products and processed foods. Saturated fats are not healthy since they can raise cholesterol. Unsaturated fats are found in nuts, avocados and oils. They are healthy and they can lower cholesterol.
Contrast and compare the structure of a fat, an oil and a phospholipid.
Phospholipids are similar to fats but they only have two fatty acids attached to glycerol. Instead of the third one, we now have Phosphate molecule. They make up cell membranes. They have both polar (hydrophilic) and nonpolar (hydrophobic) regions which is different than fatty acids. Fats usually contain saturated fatty acids and oils usually contain unsaturated fatty acids this is why fats are solid but oils are liquid.
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