Biological Molecules Flashcards
What reaction causes two monomers to join?
Condensation reaction
What is released during a Condensation reaction?
A Water Molecule
Give an example of a condensation reaction?
When two Glucose molecules join together
What chemical elements compose Nucleic Acids?
C,H,O,N,P.
What chemical elements compose Proteins?
C,H,O,N.
What Chemical elements contain Carbohydrates and Lipids?
C,H,O.
Which reaction is used to split two molecules?
Hydrolysis
What type of monosaccharide is Glucose?
A Hexose monsaccharide
On which type of Glucose molecule, Alpha or Beta, is the OH group on top?
Beta
What type of monosaccharide is Ribose?
A Pentose Monosaccharide
What bond is formed by two sugar molecules joining? ( By a condensation reaction)
A Glycosidic bond
a-Glucose + a-Glucose =?
Maltose
What TWO long-chain
a-Glucose polymers compose STARCH?
- Amylopectin
- Amylose
What is the main energy store material in plants?
Starch
Starch is a form of what?
Carbohydrate
Why is starch/Starch grains insoluble?
So as they don’t effect the water potential up and down the xylem
What type of glycosidic bonds are in Amylose?
1,4-Glycosidic bonds
What type of bonds are in Amylopectin?
1,4-Glycosidic bonds and
1,6-Glycosidic bonds
What shape does Amylose take?
Chains coil into helical shape
What shape does Amylopectin take?
Helical, and branched
Wha type of polymer is Glycogen?
Multibranched a-Glucose polymer
What material is the main energy store in animals?
Glycogen
Where is Glycogen stored?
Muscles and liver
What happens to Glycogen in times of high energy usage?
-The organs that store it,
Hydrolyse it, and break it
down into glucose molecules -Which can be used in
respiration
Is Glycogen soluble in water?
Yes
What Characteristic makes Glycogen optimal for energy storage?
-Its compact shape
takes up small space
What is the function of cellulose?
Its the major component of cell walls in plants
What type of Glucose molecule is Cellulose made from?
b-Glucose
What is the name given to a polymer of approx. 10,000 b-Glucose molecules in a long unbranched chain?
Microfibril
Multiple microfibrils create what?
Macrofibrils
What makes Cellulose highly stable?
- its composed of several polysaccharide chains running parallel to each other
- The chains have cross links between them
What type of bond creates the cross links between chains in cellulose?
Hydrogen bonds
How does this stability aid plants?
- It renders a plants strength and resistance to wind and rain
How are the atoms in water bonded?
Covalently
Why do water molecules attract each other?
Polarisation
What are the type of bonds connecting separate water molecules?
Hydrogen bonds
What is the importance of water being a solvent?
- Any polar molecule will dissolve in water
- Metabolic processes rely on chemicals being able to react together in solutions
- Allows cells to maintain concentration gradients
What is the role in living organisms, of water being a solvent?
- 70-95% of cytoplasm is water
- Important chemical reactions take place here
What is the importance of the cohesive properties of water?
- Water molecules stick together, creating surface tension
What is the role of water cohesion in living organisms?
- Transport of water in xylem relies on cohesion of water
- This allows some small organisms to walk on water
What is the importance of the freezing of water?
- It forms ice
- Ice is less dense than water and floats
What is the role of water freezing in living organisms?
- Ice floats to the top allowing organisms to survive under it
What is the importance of the thermal stability of water?
- Large bodies of water have fairly constant temps
What is the role of waters’ thermal stability in living organisms?
- Oceans provide a thermally stable environment
- Evaporating used as a cooling mechanism
What is the importance of waters’ metabolic properties?
- Chemically inert
- It’s a reactant in important chemical processes
What is the role in living organisms of waters’ metabolic properties?
- it’s used in hydrolysis/ photosynthesis
- Very predictable, won’t produce any unexpected products
What are triglycerides and Phospholipids examples of?
Macromolecules
What two things are Triglycerides composed of?
Glycerol + 3 fatty acids
What type of bond holds the glycerol and fatty acids in triglycerides together?
Ester bonds
What is used to break down ester bonds?
Hydrolysis
What makes a fatty acid ‘Unsaturated’?
A C=C double bond
Which feature in an ‘Unsaturated’ fatty acid creates ‘kinks’ in the chain?
The C=C bonds
What effect does ‘Kinking’ have on the fluidity of the ‘Unsaturated’ fatty acids?
Makes them more fluid than saturated fatty acids
Why do C=C bonds create ‘kinks’ in unsaturated fatty acids, and subsequently make them more fluid?
- Kinks mean they can’t lay as close
- cannot lay parallel, and are forced apart
Which is likely to be more fluid at a set temp, unsaturated or saturated fatty acids?
Unsaturated fatty acids
Which 3 molecules are Lipids composed of?
C,H,O
Which component of Lipids, is the least abundant? (In the lipid)
Oxygen
- It is mostly C, and H
Are lipids soluble in water?
No
Are lipids soluble in alcohol?
Yes
Why are lipids, NOT classed as polymers?
- They aren’t made of repeating units (like proteins)
What functional group is attached to Triglycerides?
Carboxylic acid, -COOH
What name is given to Triglycerides that we cannot make, so we must ingest them whole?
Essential triglycerides
Why are fatty acids, ‘acids’?
In solution they can ionise to from COO- + H+
- ( If it can form an H+ ion, it is an acid)
What is the name given to fatty acids with MORE than one C=C double bond?
Polyunsaturated fatty acids
What is the name given to fatty acids with ONE C=C double bond?
Monounsaturated
Give the 5 functions of Triglycerides
- Buoyancy
- Energy source
- Energy store
- Mechanical protection
- Insulation
Why is the insolubility of Triglycerides important cellularly?
It means fats can be stored in cells, without disrupting the cells water potential
What would happen to a cell if Triglycerides were soluble and entered the cell?
- Water would move into the
cell, causing it to swell/burst
What 3 types of molecule compose Phospholipids?
Glycerol, fatty acids, and a phosphate group
How does the new phosphate group come about in phospholipids?
A condensation reaction
In phospholipids, what thing will be the same in BOTH fatty acids?
The number of carbons
16/18
Phospholipids have both Hydrophobic and Hydrophilic parts. What word is used to describe this?
Amphipathic
Why is the phospholipid bilayer called the ‘ Fluid-mosaic’ model?
- The phospholipids are free to
move around and jostle
What type of molecule can pass through the phospholipid bilayer?
Small, non-polar, molecules
What type of bond is found in cholesterol?
An Ester bond
The general structure of all amino acids involves one ‘central’ Carbon atom with bonds to which 4 groups:
- Hydrogen atom
- Carboxyl group
- Amine group
- R group
By which bond are amino acids joined?
Peptide bonds
How is a peptide bond formed?
A condensation reaction
Which two parts of amino acids cause a condensation reaction, and thus a peptide bond?
The ‘OH’ of the Carboxylic acid, and the ‘H’ of the Amine group
What type of bond is a peptide bond?
A covalent bond
What does the protein structure determine?
The overall function of the protein
Define the ‘Primary structure’ of a protein’.
The/A sequence of amino acids.
Define the Secondary structure of a protein.
The coiling/folding of the amino acid chain
- (into a-helix/ b-pleated sheet)
What type of bonding is involved in the secondary structure of proteins?
Hydrogen bonding
Why is secondary protein structure affected by Temperature change?
Because the hydrogen bonds involved are weak, and easily disrupted by kinetic energy
How do you work out percentage difference?
difference/initial
What two shapes can from in secondary protein structure?
- A-helix
- B-pleated sheets
Give the definition of tertiary protein structure
When the a-helices, and b-pleated sheets fold.
What causes a disulphide bond/bridge?
Two ‘S’ near each other, connected
What 4 types of bonds effect tertiary and quaternary protein structure?
- Hydrophilic/Phobic interaction
- Ionic bonds
- Hydrogen bonds
- Disulphide bonds/bridges
Give the definition of Quaternary protein structure
How multiple polypeptide chains are arranged to make a protein
What two categories are 3D proteins sorted into?
- Fibrous and Globular
Which type of 3D protein is compact?
Globular proteins
Which type of protein has repetitive primary structure, and simple secondary structure?
Fibrous
What roles are given generally to fibrous proteins?
Structural roles
What roles are given to globular proteins?
Metabolic roles
What type of protein has more complex secondary structure, and primary structure that doesn’t follow a strict pattern?
Globular proteins
What makes Globular proteins suitable for metabolic roles?
They are soluble
Which type of protein is more sensitive to PH/Temp change?
Globular
Name 3 fibrous proteins
- Collagen
- Elastin
- Keratin
Collagen: Fibrous or Globular?
Fibrous
Elastin: Fibrous or Globular?
Fibrous
Keratin: Fibrous or globular?
Fibrous
Name 4 places collagen is found
- Bones
- Cartilage
- Arteries
- Tendons
What does collagen do?
Provide mechanical strength
What does keratin do?
Provides mechanical strength
What allows keratin to create mechanical strength?
Presence of Cysteine
Why does the presence of Cysteine allow keratin to make things strong?
Cysteine presence gives rise to the formation of disulphide bonds
What two aspects of Elastins’ structure give it mechanica strength?
Coiling and cross linking
Name three places that elastin can be found
- Arteries
- Skin
- Lungs and Bladder
Give 3 types of Globular protein
- Insulin
- Pepsin
- Haemoglobin
How many polypeptide chains make up Haemoglobin?
4
What are ‘Haem groups’?
Prosthetic groups
What iron do Haem groups contain?
An Iron ion
The presence of Haem prosthetic groups make Haemoglobin a what?
A conjugated protein
What is the function of Haemoglobin?
To carry oxygen from the lungs to the tissue
How many polypeptide chains are present in Insulin?
2 (1a+1b)
Both chains in the structure of insulin form what?
Their quaternary structure
What type of bond links the two chains of insulins’ structure?
Disulphide bonds
What does each chain in insulin’s structure contain?
outer , hydrophilic r groups
What is pepsin?
A stomach enzyme that digests proteins
What is the stationery phase in TLC?
-Chromatography paper/plate
What is the mobile phase in TLC?
The solvent for the molecules
