Biochemistry
Amino Acids And Protein Structure
Compiled By Simon Mwangi
Edition: 2024/25
, Science | Biochemistry I of V pages
1. L-alpha-AA is a ___ acid with an amino group on carbon ___
carboxylic; 2 (the alpha carbon)
2. What is the role of the Hydrogen on an AA
prevents bulkiness and allows side chains to fit
3. Almost all AAs are ___ AAs
L-alpha
4. How many AAs are coded for by DNA?
20
5. What are the non polar AAs?
glycine, alanine, proline, valine, leucine, isoleucine
6. What are the aromatic AAs?
phenylalanine, tyrosine, tryptophan
7. What are the polar, uncharged AAs?
asparagine, glutamine, serine, threonine
8. What are the sulfur-containing AAs?
Methionine, Cysteine
9. What are the negatively charged AAs?
aspartate, glutamate
10. What are the positively charged AAs?
arginine, lysine, histidine
11. Aspartate has a pKa of 3.9. Give the ratio of COOH to COO- at a pKa of 2.9, 1.9, and 4.9
pKa 2.9: 10 times more COOHpKa 1.9: 100 times more COOHpKa 4.9: 10 times more COO- or 10 times less
12. What is the isoelectric point?
at a certain pH, there will be an equal number of postive and negative charges
13. In regards to protein structure, what is unique about the isoelectric point
proteins are least stable at pI
14. This AA forms disulfides
cysteine, between 2 cysteine molecules
15. disulfide bridges have what affect on protein structure?
stability
16. This is found in only a few enzymes and is incorporated via a specialized tRNA which is then incorporated
Selenocysteine
Biochemistry 2024/25 Edition
Amino Acids And Protein Structure
Compiled By Simon Mwangi
Edition: 2024/25
, Science | Biochemistry I of V pages
1. L-alpha-AA is a ___ acid with an amino group on carbon ___
carboxylic; 2 (the alpha carbon)
2. What is the role of the Hydrogen on an AA
prevents bulkiness and allows side chains to fit
3. Almost all AAs are ___ AAs
L-alpha
4. How many AAs are coded for by DNA?
20
5. What are the non polar AAs?
glycine, alanine, proline, valine, leucine, isoleucine
6. What are the aromatic AAs?
phenylalanine, tyrosine, tryptophan
7. What are the polar, uncharged AAs?
asparagine, glutamine, serine, threonine
8. What are the sulfur-containing AAs?
Methionine, Cysteine
9. What are the negatively charged AAs?
aspartate, glutamate
10. What are the positively charged AAs?
arginine, lysine, histidine
11. Aspartate has a pKa of 3.9. Give the ratio of COOH to COO- at a pKa of 2.9, 1.9, and 4.9
pKa 2.9: 10 times more COOHpKa 1.9: 100 times more COOHpKa 4.9: 10 times more COO- or 10 times less
12. What is the isoelectric point?
at a certain pH, there will be an equal number of postive and negative charges
13. In regards to protein structure, what is unique about the isoelectric point
proteins are least stable at pI
14. This AA forms disulfides
cysteine, between 2 cysteine molecules
15. disulfide bridges have what affect on protein structure?
stability
16. This is found in only a few enzymes and is incorporated via a specialized tRNA which is then incorporated
Selenocysteine
Biochemistry 2024/25 Edition
