biological molecules Flashcards
Define GLOBULAR PROTEINS
COMPACT
WATER SOLUBLE
HAVE HYDROPHOBIC R GROUPS ON THE OUTSIDE OF THE PROTEIN
name some GLOBULAR PROTEINS
INSULIN
HAEMOGLOBIN
AMYLASE
ENZYMES
define the protein INSULIN and function
HORMONE INVOLVED IN THE REGULATION OF BLOOD GLUCOSE CONCENTRATION
NEED TO BE SOLUBLE
HORMONES NEED TO FIT INTO THE SPECIFIC RECEPTORS ON CELL SURFACE MEMBRANES
define CONJUGATED PROTEINS
GLOBULAR PROTEINS
CONTAIN A NON PROTEIN COMPONENT - PROSTHETIC GROUP
PROTEINS WITHOUT A PROSTHETIC GROUP IS CALLED A SIMPLE PROTEIN
DEFINE HAEMOGLOBIN AND FUNCTION
RED PIGMENT FOUND IN RED BLOOD CELLS
QUATERNARY PROTEINS WITH 4 POLYPEPTIDE
2 ALPHA SUB UNITS AND 2 BETA SUB UNITS
EACH SUBUNIT CONTAINS A PROSTHETIC GROUP OF HAEM
FE2+
THE FE2+ COMBINES REVERSIBLY WITH AN OXYGEN MOLECULE
DEFINE CATALASE AND ITS FUNCTION
QUATERNARY PROTEIN WITH 4 HAEM PROSTHETIC GROUPS
AS HYDROGEN PEROXIDE IS A BY PRODUCT OF METABOLISM AND IS DAMAGING TO CELLS, THE ENZYME CATALYSE BREAKS IT DOWN TO WATER AND OXYGEN
DEFINE FIBROUS PROTEINS
long
insoluble
due to high proportion of amino acids with hydrophobic r groups in their primary structure
name some FIBROUS PROTEINS
keratin
elastin
collagen
define KERATIN and its function
present in HAIR SKIN NAILS
has a large proportion of sulfur containing amino acids cysteine
resulting in many strong disulfide bridges forming strong,inflexible and insoluble materials
unpleasant smell of hair due to burning of sulfur
define ELASTIN and its function
found in elastic fibres
present in the walls of the blood vessels in the alveoli giving flexibility to expand
is a Quaternary protein made from tropoelastin
define COLLAGEN and its function
found in skin tendons ligaments and the nervous system
made of 3 polypeptides wound giving it flexibility
what are calcium ions responsible for (Ca2+)
nerve implusle transmission
muscle contraction
what are sodium ions responsible for (Na+)
nerve implulse transmission
kidney function
what are sodium ions responsible for (K+)
nerve impluse transmission
stomatal opening
what are hydrogen ions responsible for (H+)
catalysis of reactions
pH determination
what are ammonium ions responsible for (NH4+)
production of nitrate ions by bacteria
what are nitrate ions responsible for (NO3-)
nitrogen supply to plants for
amino acid and protein formation
what are hydrogen carbonate ions responsible for (HCO3-)
maintenance of blood pH
what are chloride ions responsible for (Cl-)
balance positive charges of sodium and potassium ions in cells
what are phosphate ions responsible for (PO4^3-)
cell membrane formation
nucleic acid and ATP formation
bone formation
what are hydroxide ions responsible for (OH-)
catalysis of reactions
pH determination
what does a nucleotide consist of
a pentose sugar
a phosphate group
a nitrogenous base
what bonds are between base and phosphate
phosphodiester bonds
what does DNA stand for
deoxyribonucleic acid
bases can be divided into which 2 groups
pyrimidines- CT - single bonds
purines - AG - double bonds
what is the job of RNA
as DNA chromosome is too large it cannot across the nucleolus therefore RNA transcripts the DNA molecules mRNA which is shorter than the whole chromosome
describe and explain the DNA replication
an enzyme DNA helicase causes the two strands of the DNA to unravel and separate
due to this free nucleotide have been activated to their complementary bases
nucleotides are joined together by DNA polymerase
each new molecule of dna is composed of one original strand and one newly formed molecule
semi conservative replication
describe the structure of glycogen
- joined by 1,4 and 1,6 glycocidic bonds
- large number of side branches
- stored in muscles and liver
- relatively large but compact
- it is insoluble
what is the structure of a amino acid
- NH2-C-H-R-COOH
what type of bond is formed between amino acids
- peptide bond
- through a condensation reaction
- removing a water molecule
describe the primary structure of a protein
- is a sequence of amino acids joined together
-
describe the secondary structure of a protein
- hydrogen bonds between carboxyl and amine groups in close amino acid monomers.
- coil shape formed by a alpha helix and beta pleated sheet
- in a 3 dimensional shape
- polypeptides chains formed
describe the tertiary structure of a protein
- folding and coiling of a protein into its final shape
- brings R groups of amino acids together
- hydrogen bonds formed
- ionic bonds
- disulfide bonds
- hydrophobic and hydrophilic interactions
describe the Quaternary structure of a protein?
- two or more polypeptides joined together
- Many proteins are made up of multiple polypeptide chains, often referred to as protein subunits.
explain the break down of peptides ?
- water molecule is used to break the peptide bonds in a hydrolysis reaction
- forming the carboxyl and amine group
what is a triplet code
- is a particular sequence of 3 bases
- that codes for a specific amino acid
what do cells need energy for?
- movement
- synthesis
- transport
what does ATP stand for?
adenosine triphosphate
how does ATP releases energy
- through a hydrolysis reaction in a removal of a phosphate group and a addition of a water molecule
- ATP is hydrolysed into ADP and a phosphate ion
releasing energy
describe the structure of ATP
- ribose sugar
- joined to a base ( adenine)
- and to three phosphate groups
properties of ATP
- small
- water soluble
- releases energy in small quantities
- easily regenerated
why is ATP called universal energy currency
- it is present in
- cells
- organisms
- releases energy in small quantities
what is in a triglyceride molecule
- one glycerol molecule
- three fatty acids
what bond in between triglycerides
- ester bond
what is in a phospholipid
- 2 fatty acids
- 1 phosphate group
- 1 glyecrol atom
what are lipids
Lipids are biological macromolecules made up of carbon, hydrogen and oxygen atoms.
what is a amino acid made of
- amine group
- carboxyl group
describe the formation of a peptide bond
- condensation reaction
- between amine group of one amino acid
- and carboxylic acid group of another
- forming a water molecule
