Chapter 2-Biological molecules Flashcards
What is a macromolecule and its types
A macromolecule are very large molecules; Polysaccharide
Protein,
Nucleic acid
and these are known as polymers
what are polymers
Are large molecules made of several similar repeating sub units called Monomers and form a chain
which reaction removes water and which reaction adds water
Condensation- removes
Hydrolisis- adds
the main types of monosaccharides in carbs are
-trioses 3C
-Pentoses 5C
-Hexoses 6C
Which type of glucose molecule has the OH group ABOVE the ring
beta glucose
Functions of Monosaccharides
2*
+Helps with being a source of energy in respiration
+Used as building blocks to create polysaccharides
the 3 common examples of disaccharides are
-Lactose
-Maltose
-sucrose
What joins to form Lactose
Glucose + Galactose
what is the oxygen bridge that is formed from a condensation reaction
*bond
GLYCOSIDIC BONDS
examples of polysaccharides
starch
cellulose
glycogen
what type of glucose makes starch and glycogen
Alpha glucose
3 advantages of starch and glycogen
-inert
-insoluble
-compact
starch is made up of 2 different polysaccharides
Amylose
Amylopectin
what is the main difference between amylose and amylopectin
Amylose is unbranched/linear and follows a 1,4 bond while Amylopectin is branched following 1,6 and 1,4 bonds
cellulose forms how much percentage of the cell wall
20-40%
cellulose is made up of what type of glucose
BETA
What’s the difference between cellulose structures VS starch and Glycogen
It is turned 180 degrees so that the -OH group of C1 and C4 align.
how many cellulose molecules make a microfibril
60-70
glue like substances called _______________ hold the cellulose fibres well
*it has the word cellulose in it
Hemicellulose
advantages of having a tensile strength from the cellulose molecules
-helps in osmosis with turgor pressure, preventing the cells from bursting
the unequal distribution of charge is called a ___________
Dipole
molecules which are hydrophobic are said to be
NON-POLAR
Fatty acids contain the acid group:
-COOH
( carboxylic acid)
what is the main difference between unsaturated and saturated fats
Unsaturated -C=C-C (double bond) -fewer hydrogen bonds
Saturated -C-C-C(no double bond)- more hydrogen bonds
why are most oils unsaturated
This is because double bonds make fatty acids and lipids melt more
More than one double bond in unsaturated fats are known as
Polyunsaturated
ALCOHOL+AN ACID=
AN ESTER bond
what is a glyceride
This is an ester formed by a fatty acid combining with the alcohol glycerol
why are triglycerides insoluble in water
this is because they are non polar and have no uneven distributed charge so cannot mix freely with water
4 uses of triglycerides
-energy store
-buoyancy
-water proofing
-thermal insulation
what properties do phospholipids contain and state whether they are polar or non polar
2 fatty acids (non polar)
a phosphate group (polar)
what term is used to describe both hydrophobic and hydrophilic
amphipathic
the property of phospholipids enables it to make a ___ __________ of the _____ _______________
-phospholipid bi layer
-cell membrane
what are monomers of proteins
amino acids
what are the names of the long chains formed by proteins
-polypeptides
Instead of glycosidic bonds in amino acids, they are referred to as
_____________ bonds
-peptide bonds
which chemical element is present in proteins that isn’t in carbs
-nitrogen
List 5 functions of proteins
-ENZYMES
-Components of cell membranes
-some hormones are proteins
-Haemoglobin is protein
-collagen adds strengths to tissues
-keratin in hair and skin
-muscle contractions- actin
-storage products
which elements are present in an amine group
NH2
POLYSACCHARIDE VS POLYPEPTIDE
Polysaccharide- carbohydrate
Polypeptide- protein
where do amino acids assemble in cells
RIBOSOMES
PRIMARY SRUCTURE:
This is the type and sequence of amino acids in a polypeptide chain with covalent bonds
SECONDARY STRUCTURE:
This involves the folding of the polypeptide chain. This is due to the hydrogen bonding between the amino acids.
what are they types of secondary structures
- alpha helix
- Beta pleated sheet
difference between the quaternary structure and tertiary
Tertiary- one polypeptide chain
Quaternary - more than one polypeptide chain
describe the structure and function of Globular proteins
-Soluble
(hydrophobic groups point inwards while hydrophilic groups fold outwards)
-Physiological functions
-metabolically active
-bended and circular
-amino acid sequence is irregular
Describe how Haemoglobin is soluble
-The interactions between the HYDROPHOBIC R groups hold the haemoglobin in a 3D shape
-The HYDROPHILIC R groups point outwards maintaining the solubility of the molecule
What does the presence of the Haem group enable
allows an easier binding of oxygen molecules, with them combining with iron atoms
Describe the structure and function of Fibrous proteins
-Insoluble
-their functions are structural
-they have a repetitive amino acid sequence
-they are long strands
-an example is collagen
acronym for distinguishing the 2 proteins
S hapes
A mino acids sequence
F unction
E xamples
S olubility
how many chains do collagen fibres have
3
describe the structure of collagen
- its 3rd amino acid is always glycine allowing a tight bond
- the collagen molecule are linked with other molecules running PARALLEL with Covalent bonds leading to many collagen molecules to form fibrils
- the ends of the parallel molecules are staggered to prevent weak spots
- many microfibrils lead to fibres forming
difference between covalent bonds and hydrogen bonds
Covalent bonds- these occur due to chemical bonds sharing of electrons
Hydrogen bonds- occurs between attraction forces /oppositely charged
how is water considered a polar molecule
oxygen has a slight negative charge, hydrogen has a slight positive charge, the unequal distribution of electrons creates charges
why are water molecules hard to break
They have a large number of hydrogen bonds compared to covalent bonds
which groups are considered hydrophilic
-OH
-C=O
N-H
the dipole nature of water give its properties:
*hint 4
1)it is a solvent
2)it is a transporting medium
3)it has a high specific heat capacity
4)it has a high latent heat of vaporisation
how is water an exemplary solvent
-Because of its two opposite charges, an ion that is either charged can be attracted to the opposite charge that is on the water molecule and therefore separates them.
the high specific heat capacity of water has important biological implications, mention 2:
-Our cells which contain a high proportion of water means that temperature can be maintained and more constant than air
-Large water bodies can maintain its cool temperature which can maintain habitats
what is latent heat of vaporisation
the amount of heat energy needed to vaporise a liquid
why does water have a high latent heat of vaporisation
due to the sticking of water molecules by hydrogen bonds
what are the important biological implications of a high latent vaporisation
-can be seen in mammals when sweating occurs,
-transpiration
-when water turns into ice however, it must lose a very high amount of heat energy making it less likely for aquatic animals to freeze.
Which bonds are considered Covalent bonds and which bonds are not
COVALENT -disulfide bonds
-Peptide bonds
NOT COVALENT -Hydrogen bonds
-ionic bonds
