Topic 2: chemical basis of life Flashcards
1
Q
Define element
A
- Substance that cannot be broken down into other by chemical reaction
2
Q
Define compound
A
- Substance with 2+ elements in fixed ratio
- Different characteristics than element
3
Q
What are the essential elements for life?
A
- C + H + O + N = make up 96% of living matter
- Ca + K + Na = 4% of remaining living matter
- Trace elements are required in minute conditions = Fe + I + Se + Cu
4
Q
Give some trace element deficiencies
A
- Iodine = hypothyroidism = iodine is essential for thyroid hormone production
- Iron = anemia = iron part of haemoglobin structure
5
Q
What is the mass of the subatomic particles?
A
- P+ = 1.7x10-24g = 1 Dalton
- N = 1.7x10-24g = 1 Dalton
- e- = 1/2000 = negligible
6
Q
Describe the clinical applications of radioisotopes
A
- Disease diagnosis = imaging
- Treatment = I131 for thyroid cancer
- Assess degree of severity
- Treatment monitoring
7
Q
Describe PET scan
A
- Uses radioactive isotopes = F18
- Imaging produces 3D image of functional processes in body
- Detect gama rays emitted by radioisotope tracer in body attached to F18
8
Q
Describe hydrogen bonding
A
- Between neighboring molecules
- Between H atom covalently bonded to a electronegative atom + another electronegative atom on a molecule = O + N + F
- Between H2O molecules = between H of 1 molecule + O of other molecule
9
Q
Describe Van der Waals
A
- Positive + negative regions of molecules attract each other
- Weaker than H-bonds
10
Q
What is the role of weak chemical bonds?
A
- Reinforce shape of larger molecules
- Help neighboring molecules adhere to each other
- Important as shape of molecules important to their function in cells
