Key food molecules Flashcards
What functional groups are amino acids made up of?
A carboxyl, amine, and R functional group
How many amino acids are in a peptide?
1
How many amino acids are in a protein?
more than 50
What is an essential amino acid?
An amino acid that our bodies cannot synthesize on their own, so they must be obtained through our diet
Where do bonds between amino acids form?
between the nitrogen of one and carbon of another
What type of bond is between amino acids?
A peptide bond
Do amino acids act as bases or acids?
They can act as either depending on the pH of the environment they are in
What charge will an amino acid in high pH have and why?
negative, as a low pH indicates a basic environment, meaning the amino acid will be more likely to give up a proton resulting in a negative charge on the carboxyl group
What is the primary structure of a protein?
The sequence of amino acids in the polypeptide chain
What is the secondary structure of a protein?
Shapes that form as a result of hydrogen bonding
What is the tertiary structure of a protein?
The overall 3D shape of the protein, that forms as a result of interactions between the amino acid side chains
What is the quaternary structure of a protein?
The number of polypeptide chains in the 1 molecule
What occurs when a protein becomes denatured?
The bonds between amino acids and their side chains are broken as a result of extreme pH or high temperatures, which results in the loss of the proteins secondary, tertiary and quaternary structure hence altering its shape.
What are carbohydrates?
Polymers of Monosaccharide (simple sugar) monomers
How is maltose produced?
Glucose + Glucose = Maltose + Water
How is sucrose produced?
Glucose + Fructose = Sucrose + Water
What is the main function of polysaccharides?
To enable plants and animals to store energy/glucose
What is starch made up of?
lots of alpha glucose molecules
What are the 2 types of starch?
Amylose and amylopectin?
What form of starch is a linear polymer?
Amylose
What form of starch contains branching?
Amylopectin
Which form of starch has a higher solubility in water and why?
Amylopectin as more -OH are exposed as a result of less coiling occuring due to branching in its structure
What carb do plants use to store energy?
Starch
What carb to animals use to store energy?
Glycogen
What is cellulose used for?
As the main structural component in plant cells.
What is cellulose comprised of?
lots of beta glucose molecules
How are glucose molecules arranged in cellulose?
Every second glucose molecule is inverted
When is glycogen produced?
When animals have excess amounts of glucose in their system and hence need to store the glucose for later use
Where is glycogen generally stored?
In the liver or muscle tissue
How does Aspartame’s energy content compare to other sugars?
It has an energy content of approximately 17kj/g which is the same as fructose and sucrose
What are 2 key differences between Aspartame and other sugars?
It is artificially produced and is much sweeter than other sugars so only small quantities are required to produce a similar taste
What is the semi-structural formula for glycerol?
CH2(OH)CH(OH)CH2(OH)
What is the general formula of a fatty acid?
(Long R group)-COOH
What is the worded reaction formula that would produce a triglyceride?
Glycerol + 3 Fatty Acids = Triglyceride + 3 water
What is the difference between a saturated and unsaturated fat?
Saturated fats only contain molecules single bonds between carbon atoms, whereas unsaturated fats contain one or more double bond between carbon atoms.
What is the general formula for a monounsaturated fat?
C[n]H[2n-1]COOH
What is the general formula for a saturated fat?
C[n]H[2n+1]COOH
What is the general formula for a polyunsaturated fat?
C[n]H[2n-3]COOH
What is a omega 3 fatty acid?
A fatty acid with a double carbon bond on the 3rd carbon from the omega carbon
What is the omega carbon?
The carbon on the other end of a fatty acid from the carboxyl group
What is an essential fatty acid?
A fatty acid that our bodies cannot synthesize on their own, so we have to obtain them through our diet
Do saturated or unsaturated fats have a higher melting point and why?
Saturated fats, as they have a more linear shape which allows the fatty acid tails to pack more closely together and hence it has stronger dispersion forces between molecules.
What are vitamins?
micronutrients that are needed in our diet is small quantities
Are vitamins essential or non essential?
most are essential as our bodies cannot synthesize their own
Is vitamin D essential or non essential?
Non-essential
What is the grouping of different vitamins based on?
Their solubility in water and fat
How are vitamins different to macronutrients?
They are only needed in small amounts and there is large variation of the structures of different vitamins
What determines if a vitamin is water or fat soluble?
The amount of -OH groups it contains, which will determine if it can form hydrogen bonds with water
What is the difference between water and fat-soluble vitamins?
Water-soluble vitamins are excreted by the body and cannot be stored, whereas fat-soluble vitamins can
