Module 2: Section 2 - Biological Molecules Flashcards
What does water being di polar result in
Attracts positively and negatively charged ions towards it
How do hydrogen bonds form
Hydrogen is slightly positively charged and oxygen slightly negatively charged so these opposite charges attract to each-other forming hydrogenbonds
What does hydrophilic mean
It attracts water (water loving)
Do charges / polar molecules dissolve readily in water and if they do what are they called
Yes and are called hydrophilic
Do charges/ non polar molecules dissolve readily in water and if not what are they called
No and are called hydrophobic
What does hydrophobic mean
It repels water (water hating)
How can water resist changes in temperature
Hydrogen bonds between water molecules can absorb a lot of energy. This means they have a high specific heat capacity so it doesn’t change temperature very easily and remains at constant temperature
Why is water having a high specific heat capacity good for organisms
The constant temperature is good for organisms because it means water doesn’t experience rapid temperature changes so it’s a good habitat for them. And water inside organisms is stable which helps them maintain a constant internal body temperature
Why is water having a high specific heat capacity good for organisms
The constant temperature is good for organisms because it means water doesn’t experience rapid temperature changes so it’s a good habitat for them. And water inside organisms is stable which helps them maintain a constant internal body temperature
What is cohesion
It’s the tendency for molecules within a substance to stick together
Why are water molecules very cohesive
They are polar hydrogen bonds so can stick together
What does waters strong cohesion do
Helps water to flow which is useful for transporting substances
Gives the water a high surface tension, allowing small organisms to walk/ move on the surface of things like a pond
Is waters solid or liquid form more dense
Liquid
How are water’s density and freezing properties beneficial for organisms
Ice floats on water and insulates the water below it reducing the chances of organisms completely freezing and increasing chances of life
What are monomers
Small, identical or similar molecules,that can be joined together to make large molecules called polymers
What are polymers
Large molecules which are formed by joining many identical or very similar monomers together
What is a hexose sugar
A monosaccharide which has six carbon atoms in each molecule
What are the types of glucose
Alpha and beta
What is an isomer
Same molecular but the atoms are connected in a different way
Is glucose a hexose or Pentose sugar
Hexose
What is the difference between alpha and beta glucose
Alpha have a H on top and OH on the bottom and beta has a OH on top and H on bottom
What bonds are carbohydrates joined by
Glycosidic bonds
What bonds are proteins joined by
Peptide bonds
What bonds are lipids joined by
Ester bonds
What elements do carbohydrates contain
Carbon, hydrogen and oxygen
How are disaccharides formed
Two monosaccharides are joined by a glycosidic bond (condensation reaction) and a water molecule is released
What is glucose +glucose
Maltrose
What is glucose and fructose
Sucrose
What is glucose and galactose
Lactose
What is cellulose structure
-Polymer of beta glucose
-Made of long unbranched chains of beta glucose
- 2nd glucose is inverted so cellulose molecule is straight rather than curved
- cellulose chains linked together by hydrogen bonds to form cellulose micro fibrils and as these fibres are so strong it supports the cell
What is starch a mixture of
Two polysaccharides of alpha glucose amylose and amylopectin
What is amylose structure
-Long
- unbranched chain of alpha glucose
- 1-4 glycosidic bonds
- coiled, cylinder like structure due to the angle of glycosidic bonds
Amylopectin structure
-Long
- branched chain of alpha glucose
- side branches
-1-6 glycosidic bonds
-compact
Glycogen structure
-long branched chain
-1-4 and 1-6 glycosidic bonds
- side branches
-compact
Why are compact branches good
Good for Energy storage
What is glycogens function
Energy storage in animals, bacteria and fungi
What are triglycerides soluble in and insoluble in
Soluble in alcohol
Insoluble in water as not polar
How are triglycerides formed
1 glycerol esterified with three fatty acid
Triglycerides function
Storing energy
What are phospholipids structures
-1 glycerol esterified with two fatty acid groups and 1 phosphate group
- phosphate head is hydrophilic and polar(water soluble) and the tails are non polar and hydrophobic
What happens when phospholipids are mixed with water
Form droplet spheres with the hydrophilic heads facing the water and the hydrophobic tails facing eachother
What is amino acids general structure
-central carbon
-amino group
-carboxyl group
-hydrogen atom
-an R group
How are polypeptides formed
Condensation reactions between the amine group of one amino acid and the carboxyl group of another
What are the 4 levels of the protein structure
Primary structure, secondary structure,tertiary structure and the quaternary
What is the primary structure
The unique sequence of amino acids in the polypeptide chain
What are the bonds that hold the secondary structure of proteins together
Hydrogen bonds which cause the protein to fold into specific structures
What are two secondary structures of proteins
Alpha helix
Beta pleated sheet
Why are the secondary structure of proteins stable
Many hydrogen bonds
How does the secondary structure form
Primary polypeptide chain folds to form a secondary structure ( result of protein folding)
How does the tertiary structure form
Further foldings in the secondary structure
What are the bonds in the tertiary structure
Hydrogen bonds-which are weak
Ionic bonds- which are strong
Sulphur bridges -which are strong
How is the quaternary structure formed
The interaction between many polypeptides
Examples on quaternary structure of proteins
-collagen(protein in skin)has 3 polypeptide chains
-haemoglobin( globular proteins 4 polypeptide chains)
-insulin(2 polypeptide chains held together by disulphide bonds)
what is meant by a conjugated protein
- contains non-protein
groups - has prosthetic group
- (prosthetic group) is , iron
/ Fe , ion - (prosthetic group) is
attached by , covalent
bonds / ionic interactions
/ hydrogen bonds
what are fibrous proteins properties
-insoluble in water
-strong
-stable (unreactive)structure
-polypeptide chains form long twisted strands
-form hydrogen bonds with adjacent chains
what are globular proteins properties
-unstable (reactive) structures
-soluble
-Hydrophobic R group on the inside and hydrophilic on the outside
-Polypeptide chains roll up into spherical shape
what are 3 roles of lipids
-energy storage
-thermal insulation
-protection
What are the examples of globular proteins and what do they do
- Haemoglobin has 4 polypeptide chains and a prosthetic group called a haem, it carries oxygen around the red blood cells
- insulin is a hormone secreted in the pancreases and consists of 2 polypeptide chains
-amylase is an enzyme that catalyses the breakdown of starch
what are the examples of fibrous proteins and what do they do
-collagen is found in animal connective tissues e.g skin and is very strong
-keratin is found in skin hair nails.it can be flexible or tough
-elastin- found in elastic connective tissues such as skin . As its elastic it allows the tissue to return to its original shape
