Top Posters
Since Sunday
38
o
10
j
9
m
9
C
8
s
8
a
8
f
8
y
8
n
8
d
8
M
7
Home Q & A Board Science-Related Homework Help Physics
New Topic  
einsteindude einsteindude
wrote...
Go to Answer
Posts: 5058
Rep: 29 1
8 years ago
Describe point mutations, nonsense mutations, and frameshift mutations. Discuss the likely effect of each type of mutation on a protein being built.
Textbook 
Conceptual Physical Science

Conceptual Physical Science


Edition: 6th
Authors:
Read 702 times
2 Replies
Replies
Answer accepted by topic starter
bSharpbSharp
wrote...
#1
Top Poster
Posts: 3706
Rep: 309 0
8 years ago
Sign in or Sign up in seconds to unlock everything for free
More solutions for this book are available here
 A point mutation occurs when one nucleotide is substituted for another. Point mutations sometimes change the sequence of amino acids in a protein. For example, a mutation from AAC to AAG would replace asparagine with lysine. Not all point mutations affect amino acids, however: A mutation from GCA to GCC would have no effect because both codons code for alanine. Does a change in a single amino acid really matter? Sometimes it does and sometimes it doesn't. The sickle cell hemoglobin allele differs from normal hemoglobin by only one amino acid. In addition, for proteins that function as enzymes, the lock-and-key fit of enzyme to substrate can be disrupted by a single amino acid change. A nonsense mutation creates a stop codon in the middle of a protein-coding sequence. Nonsense mutations result in the production of shorter, often nonfunctional proteins. The insertion and deletion of nucleotides can result in a frameshift mutation. In a frameshift mutation, the triplet codons that are "read" and translated are shifted, completely altering the amino acid sequence in the protein being assembled. Frameshift mutations usually have significant disruptive effects on proteins.
 
This verified answer contains over 190 words.
1

Related Topics

wrote...
#2
8 years ago
Super! Don't forget to mark my post as best answer Grinning Face
New Topic      
Quick Reply
Explore
Post your homework questions and get free online help from our incredible volunteers
  342 People Browsing
 196 Signed Up Today
Start New Topic Take the Tour CoursesNew Study Tools Topics Trending Browse by Textbook
Live Chat
Related Images
  
 271
  
 261
  
 257
Your Opinion
Where do you get your textbooks?
Votes: 218
Previous poll results: Which industry do you think artificial intelligence (AI) will impact the most?