Biological Molecules 1 Flashcards
What are all carbohydrates made up of?
Carbon, hydrogen and oxygen
What are monosaccharides?
Simple sugars where there is one oxygen present and two hydrogen atoms present for each carbon atom.
What is the general formula for monosaccharides?
(CH2O)n
What is the formula for triose sugars?
C3H6O3
What is the formula for pentose sugars?
C5H10O5
What is the formula for hexose sugars?
C6H12O6
What are some examples of pentose sugars?
Ribose and deoxyribose, important in DNA and RNA.
What are some examples of hexose sugars?
Glucose, fructose and galactose
What is a disaccharide made up of?
Two monosaccharides joined together
How do two monosaccharides join together to form a disaccharide?
Condensation reaction (H2O molecule removed)
What is the bond in a disaccharide?
Glycosidic bond
What monosaccharides join to make sucrose?
a-Glucose and fructose
What monosaccharides join to make lactose?
a-Glucose and b-Galactose
What monosaccharides join to make maltose?
a-Glucose and a-Glucose
What are polysaccharides?
Many monosaccharides joined together by condensation reaction, joined by glycosidic bonds.
How is a polysaccharides structure ideal for storage?
-They can form compact molecules
-Glycosidic bonds are easily broken, allowing rapid release of monosaccharides.
How does the structure of amylose and amylopectin differ?
Amylose forms a spiral chain, made purely of 1,4-glycosidic chains
Amylopectin forms branching chains as it has 1,4 and 1,6-glycosidic chains.
How is amylose’s structure related to the function?
The coiled structure allows the molecule to be compact, making it good for storage
How is amylopectin’s structure related to the function?
Branched structure so it is broken down more quickly so glucose can be released when needed
What isomer of glucose is cellulose made up of?
B-Glucose
Why is B-glucose in cellulose inverted?
So that hydroxyl groups stick out on both sides and hydrogen bonds form between the chains to form microfibrils.
How is cellulose’s structure related to its function?
Microfibrils are strong, which provides the cell wall with strength so it can support the plants structure.
What is glycogen made up of?
a-Glucose
What is glycogen’s structure?
1,6-glycosdic bonds give glycogen a branched structure and it is stored as small granules.
How is glycogen’s structure related to its function?
Less dense and more soluble than starch and broken down more rapidly due to the branched structure.
What is the function of lipids?
Form an Important integral part of cell membranes as an energy store.
What is the chemical formula of glycerol?
C3H8O3
How are fatty acids and glycerol combined?
Using ester bonds
How do fatty acids differ?
-The length of the carbon chain
-The fatty acid may be saturated or unsaturated
What is a saturated fatty acid?
Each carbon atom is joined to the one next to it by a single covalent bond
What is an unsaturated fatty acid?
The carbon chains have one or more double covalent bonds in them.
What is one example of a saturated fatty acid?
Stearic acid
What is an example of a polyunsaturated fatty acid?
Linoleic acid
How is a fat or oil produced?
An ester bond is formed between glycerol and one, two or three fatty acids in a condensation reaction.
What is esterification?
The formation of ester bonds.
Are lipids containing saturated fatty acids going to solid or liquid at room temperature?
Solid
Why is lipids hydrophobic nature important in plants?
Plants use lipids as waxes for waterproofing their outer surfaces to minimise the loss of water.
What are two other characteristics of lipids, except from being hydrophobic?
-Good insulators (myelin sheath)
-Low density (float easily)
Are lipid tails hydrophobic or hydrophilic?
Hydrophobic
What does hydrophobic mean?
Does not dissolve in water
What is a micelle?
A spherical formation of molecules in water with hydrophobic areas in the middle and hydrophilic areas outside.
What is the structure of a phospholipid?
Phosphate-Glycerol-Hydrophobic tail
What reaction joins amino acids together?
Condensation reaction
What bonds form between amino acids?
Peptide bonds
What is a chain of hundreds of amino acids called?
Polypeptide chain
What three bonds are present in proteins?
-Hydrogen bonds
-Disulfide bonds
-Ionic bonds
What is the primary structure of a protein?
The sequence of amino acids that make up the polypeptide chain.
What is the secondary structure of a protein?
The arrangement of the polypeptide chain into a regular structure, held by hydrogen bonds
What are two examples of secondary protein structures?
a-helix
b-pleated sheets
What is the tertiary structure of a protein?
The three-dimensional folding of the secondary structure
What proteins are an example of a tertiary structure?
Globular proteins
What is the quaternary structure of a protein?
The three-dimensional arrangement of more than one tertiary polypeptide.
What are some characteristics of fibrous proteins?
-insoluble in water
-very strong, appearing in the structure of connective tissue
What is the structure of fibrous proteins?
-little or no tertiary structure
-Long, parallel polypeptide chains with occasional cross-linkages
What is an example of a fibrous protein?
Collagen
How many polypeptide chains are collagen made up of?
Three
How are the polypeptide chains arranged in collagen?
In a triple helix, held together by lots of hydrogen bonds
Where is collagen found?
Tendons, bones and skin
What is an example of a globular protein?
Haemoglobin
What is the structure of a globular protein?
Complex tertiary sometimes quaternary structures, folded in spherical shapes.
How many polypeptide chains are in haemoglobin?
Four
What bonds are between the polypeptide chains in haemoglobin?
Disulfide bonds
What are conjugated proteins?
Protein molecules that are joined to another molecule called a prosthetic group.
What prosthetic group is haemoglobin joined to?
Iron-containing prothetic group
What are glycoproteins?
A protein with a carbohydrate prosthetic group
What is the function of glycoproteins?
To hold onto a lot of water to be used as lubricants (eg, mucus)
What are lipoproteins?
A protein with a lipid prosthetic group
What is the function of lipoproteins?
To transport cholesterol in the blood
What are the two main forms of lipoproteins in the blood?
Low-density lipoproteins (LDLs)
High-density lipoproteins (HDLs)
What is the test for proteins?
-Add biuret solution
-A purple colour indicates protein presence
