Fibrous and Globular proteins Flashcards
1
Q
What are characteristics of globular proteins?
A
- compact, water soluble
- spherical shape
- form when proteins fold into tertiary structures
- easily transported around organisms
- have metabolic roles in organisms
2
Q
What are example of globular proteins?
A
- haemoglobin
- insulin
- amylase
3
Q
How is haemoglobin a globular protein?
A
- 4 polypeptide chains joined together
- carries oxygen around the body
- conjugated protein - its a protein with a non-protein attached to it
- proshetic group - haem
- haem contains iron which oxygen binds to
4
Q
How is insulin a globular protein?
A
- a hormone secreted by the pancreas
- helps to regulate the blood glucose level
soluble - can be transported around the blood - consists of two polypetide chains - held by disulfide binds
5
Q
How is amylase a globular protein?
A
- made from one polypeptide chain
- twisted and folded
- an enzyme that catalyses the break down of starch in the digestive system
6
Q
What are the characteristics of fibrous proteins?
A
- metabolically inactive
- strong
- have structural roles
- not water soluble
- formed from long, insoluble molecules
7
Q
What are examples of fibrous proteins?
A
- keratin
- elastin
- collagen
8
Q
How is keratin a fibrous protein?
A
- strong and flexible
- made from 2 parallel alpha helices twisted around each other
- disulfide bonds
- hair contains fewer bonds making it more flexible than nails
9
Q
How is elastin a fibrous protein?
A
- stretches and recoils
- elastic fibres in blood vessels and surrounding alveoli in lungs
- made up of stretchy fibres - tropelastin
- breathe in, alveoli stretches
- heart contracts, blood is forced into our arteries, the walls stretch
10
Q
How is collagen a fibrous protein?
A
- strong but flexible
- connective tissue found in skin, ligaments, nervous system
- made up of three polypeptide wound together in a long and strong rope like structure
11
Q
What are two computer modelling technqiues for protein structure?
A
- ab initio protein modelling - uses information to predict the possible outcomes in terms of secondary and tertiary structure of final protein
- comparative protein modelling - scans amino acids sequence against data base of know protein structures
