Biological Molecules 1 Flashcards
What is a polymer
Large complex molecules composed of long chains of monomers joined together
What type of reaction forms polymers
Condensation reaction ( removal of a water molecule)
What type of reaction breaks down polymers
Hydrolysis ( addition of a water molecule)
What elements make up a carbohydrate molecule
Oxygen
Hydrogen
Carbon
What are the monomers that carbohydrates are made from
Monosaccharides
Give examples of some monosaccharides
Alpha glucose
Beta glucose
Fructose
Galactose
What is a disaccharide
Two monomers joined together via a condensation reaction
What bond forms between two monosaccharides
Glycosidic bonds
Give examples of disaccharides and there monosaccharides
Alpha glucose + alpha glucose =Maltose
Alpha glucose + fructose =Sucrose
Alpha glucose + galactose =Lactose
What is a polysaccharide
When more than two monosaccharides are joined together via a condensation reaction ,
Forming glycosidic bonds
Give 3 examples of polysaccharides
Starch
Glycogen
Cellulose
What is the structure and the functions of starch
Amylose
Structure = long unbranched chain of alpha glucose.
Coiled structure
Function = this makes it really compact and so is therefore a good storage molecule because it can fit in small spaces
Amylopectin
Structure = long branched chains of alpha glucose
Function = branched chains allow for enzymes to breach down the molecules easily because of the glycosidic bond is more exposed . Meaning glucose and be released more easily.
Insoluble in water so doesn’t affect water potential ,therefore is a good storage molecule.
What is the structure and function of glycogen
Structure = a polysaccharide of alpha glucose with lots of side chains
Function= this means that enzyme’s can easily access the bonds to break them meaning it can be a quick real ease of energy .
It is also a very compact molecule which is good for storage.
Important energy store in animals.
What is the structure and function of cellulose
Structure =long unbranched chain of beta glucose. Bonded together to form straight chains .
These straight chains are held together by hydrogen bonds forming microfibrils
Function =these strong fibres means that cellulose provide structural support for plants in the cell walls
What is the test for starch
Iodine solution test
Positive =blue-black
Negative=browny-orange
What are the main two types of lipids
Triglycerides
Phospholipids
What molecules make up a triglyceride
One glycerol molecule
Three fatty acids molecules
What is special about the fatty acid tails on triglycerides
They are hydrophobic so repel water
What does the fatty acid tail make a triglyceride
Insoluble in water
What are the two types of fatty acids
Saturated fatty acids
Unsaturated fatty acids
What is a saturated fatty acid
When the R group of the fatty acid only contains single bonds
How are triglyceride formed
Condensation reaction
What bonds form between molecules in a triglyceride
Ester bonds
What makes up a phospholipid
One glycerol molecule
Two fatty acid molecules
One phosphate group
What is special about the phosphate group
It is hydrophilic ( attracts water )
What is special about the fatty acid molecules
They are hydrophobic ( repel water )
What is the main usage of triglyceride
Energy storage molecule
Insoluble in water so they don’t effect water potential
Hydrophobic tails face inwards
What are the main properties of phospholipids
Make a phospholipids bilayer
With hydrophobic tails inwards
With hydrophilic heads facing outwards
What is the test for lipids
Emulsion test
Shake substances in a test tube with ethanol
Then add to water
Positive test = produced a milky emulsion
What are the monomer of proteins
Amino acids
What is formed when two amino acids join together
Dipeptide
What are many amino acids bonded together known as ?
Polypeptide
What is the general structure of an amino acid
A carboxyl group (COOH) an amine group (NH2) and a variable R group
What reaction joins two amino acids together
Condensation reaction
What bonds form between amino acids
Peptide bonds
What is the primary structure of a protein
The basic sequence of amino acids in the polypeptide chain
What is the secondary structure of proteins
When hydrogen bonds form between the amino acid chain , forming a basic shape , cooling into an alpha helix or folded into a beta pleated sheet
What is the tertiary structure of a protein
The overall 3D shape of the protein where more bonds form between different sections of the of the polypeptide chain ,
Such as :
Ionic bonds
Hydrogen bonds
Disulfide bridges
What is the Quaternary structure of a protein
The way the 3D polypeptide chains are assembled together , the overall final 3D shape ( not all proteins have a quaternary structure , only if it contains more than one polypeptide chain )
Give examples of proteins in the body
Enzymes
Hormones
Antibodies
Structural proteins ( Keratin )
Transport proteins
What is the test for proteins
Biuret test
Add sodium hydroxide solution
Then add copper sulfate solution
Positive = purple
