Chapter 3- Biological Molecules Flashcards
What is an ion?
An atom or molecule in which the total number of electrons is not equal to the total number of protons
Which elements do Carbohydrates contain?
Carbon, hydrogen and oxygen
What is the general formula for Carbohydrates?
Cx(H2O)x
Which elements do Lipids contain?
Carbon, hydrogen and oxygen
Which elements do Proteins contain?
Carbon, hydrogen, oxygen, nitrogen and sulfur
What inter molecular forces are present in water molecules?
Hydrogen bonding
Name some properties of water that make it great for supporting life.
High boiling point
Ice is less dense than water
It is cohesive
It is polar
Why is being a polar molecule good for water as it can be used as a solvent?
Many solutes in an organism can dissolve in it, as many solutes are also polar so water can act as a transport medium for dissolved compounds and as a medium for chemical reactions to take place.
How does water act as a coolant?
It takes a large amounts of energy to break the hydrogen bonds between molecules, meaning that water will stay a fairly constant temperature inside the body
What is the difference between alpha and beta glucose?
If the -OH group attached to it is below the ring, the molecule is alpha glucose. If the -OH group is above the ring, the molecule is beta glucose.
What 2 monosaccharides condense to form maltose?
2 alpha glucose
What 2 monosaccharides condense to form cellulose?
2 beta glucose molecules
What is special about the formation of cellulose?
one beta glucose must rotate 180 degrees in order for the OH groups to come close enough together
What 2 monosaccharides condense to form sucrose?
one alpha glucose and one fructose
Name 3 hexose monosaccarides.
Glucose, Fructose and Galactose
What 2 monosaccharides condense to form lactose?
Galactose and glucose
Name a pentose monosaccharide.
ribose
Which 2 bonds are present in starch
1,4 glycosidic bonds between alpha glucose molecules on the amylopectin and 1,6 glycosidic bonds between the glucose molecules on the brach intersections (every 25 molecules)
What is Hydrolysis?
The adding of water to break a glycosidic or polypeptide bond
What chemical is used to test for Reducing and Non-reducing sugars?
Benedict’s Reagant
What chemical is used to test for starch?
Iodine
What is a triglyceride?
Made by combing one glycerol molecule with 3 fatty acids (these contain a carboxyl group (-COOH))
Do saturated lipids have a double bond?
No
Describe a monounsaturated lipid
A Lipid with just one double bond
Why are polyunsaturaed lipids liquids/ oils?
The double bonds cause the molecule to bend. They cannot pack together closely so less energy is needed to break the inter molecular bonds between the molecules.
What are phospholipids?
modified triglycerides where one fatty acid is replaced with a phosphate group (PO4 3-)
Which end of a phospholipid is hydrophobic?
The tails (but the readily mix with fat)
Which end of a phospholipid is hydrophilic?
the heads
Give 4 roles lipids have because of their non polar nature.
membrane formation
Hormone production
electrical insulation for impulse transmission
waterproofing
What are proteins made of?
amino Acids
What results in different amino acids?
different R groups
What is the bond between 2 amino acids called?
A peptide Bond
What is the resulting compound after condensation of 2 amino acids called?
A dipeptide
What is the primary structure of a protein?
The sequence in which the amino acids are joined
What is the secondary structure of a protein?
The shape the molecule becomes because of Hydrogen bonding. (Alpha helicies and Beta Pleated sheets)
What is the tertiary structure of a protein?
The folding of a protein into its final shape. It often includes sections of secondary proteins.
What is the quaternary structure of a protein?
Results from the association of two or more individual proteins called subunits.
Describe globular proteins
Compact, water soluble, and usually spherical in shape.
Explain how globular proteins form.
Form when proteins fold into their tertiary structures in such a way that the hydrophobic R groups on the amino acids are kept away from the aqueous environment. This means that proteins are soluble in water.
What is a conjugated protein?
A globular protein that contains a non protein component called a prosthetic group.
Give some examples of a prosthetic group.
Lipids (Lipoproteins), Carbohydrates (Glycoproteins), Haem groups
What is haemoglobin made of?
2 alpha helices, 2 beta pleated sheets with 4 haem groups
Describe how fibrous proteins form
Formed from long, insoluble molecules. This is due to the high proportion of amino acids with hydrophobic R groups in the primary structure.
Give 3 examples of fibrous proteins and give a use for each.
Keratin (present in hair, skin), Elastin (Walls of blood vessels), Collage (connective tissue found in tendons, ligaments etc.)
What do fibrous proteins tend to make?
Strong, long molecules which are not folded into complex 3D shapes like globular proteins.
What roles do Calcium Ions Have?
Nerve impulse transmission and muscle contraction
What roles do Sodium Ions Have?
Nerve impulse transmission and kidney function
What roles do Potassium Ions Have?
Nerve impulse transmission and stomatal opening
What roles do Hydrogen Ions Have?
Catalysis of reactions, pH determination
What role do Ammonium Ions Have?
production of nitrate ions in bacteria
What role do Nitrate Ions Have?
Nitrogen supply to plants for amino acid and protein production
What role do Hydrogen Carbonate Ions Have?
Maintenance of blood pH
What role do Chloride Ions Have?
Balance positive charge of sodium and potassium ions in cells
What roles do Phosphate Ions Have?
Cell membrane formation, nucleic acid and ATP formation, bone formation
What roles do Hydroxide Ions Have?
Catalysis of reactions, pH determination
