Skip to main content

The salient features of genetic code


The salient features of genetic code

(i)The codon is triplet. 61 codons code for amino acids and 3 codons donot code for any amino acids, hence they function as stop codons.

(ii)One codon codes for only one amino acid, hence, it is unambiguous and specific

(iii)Some amino acids are coded by more than one codon, hencethe code is.
degenerate

(iv)The codon is read in mRNA in a contiguous fashion. There areno punctuations.

(v)The code is nearly universal:for example, from bacteria to human UUU would code for Phenylalanine (phe). Some exceptions to thisrule have been found in mitochondrial codons, and in someprotozoans.

(vi)AUG has dual functions. It codes for Methionine (met) , and it also act as
initiator codon

Comments

Post a Comment

Popular posts from this blog

Emasculation and Bagging

If the female flower is bisexual , removal of anthers from the flower bud before the anther dehisce using a pair of forceps this is called emasculation . Emasculated flowers have to be covered with a bag of suitable size made of butter paper to prevent contamination of its stigma with unwanted pollen . this process is called bagging 

Cell Death Discovery Suggests New Ways to Protect Female Fertility

 Melbourne researchers have identified a new way of protecting female fertility, offering hope to women whose fertility may be compromised by the side-effects of cancer therapy or by premature menopause. The researchers, from the Walter and Eliza Hall Institute, Monash University and Prince Henry's Institute of Medical Research, made the discovery while investigating how egg cells die. They found that two specific proteins, called PUMA and NOXA, cause the death of egg cells in the ovaries. The finding may lead to new strategies that protect women's fertility by blocking the activity of these two proteins. Associate Professor Clare Scott from the Walter and Eliza Hall Institute said the research showed that when the DNA of egg cells is damaged following exposure to radiation or chemotherapy, such as that received during some cancer treatments, PUMA and NOXA trigger the death of the damaged eggs. This egg cell death causes many female cancer patients to become infertile. &q

Rhodophyceae

Rhodophyta are commonly called red algae because of the predominance of the red pigment, r-phycoerythrin in their body. Majority of the red algae are marine with greater concentrations found in the warmer areas. They occur in both well-lighted regions close to the surface of water and also at great depths in oceans where relatively little light penetrates. The red thalli of most of the red algae are multicellular. Some of them have complex body organisation. The food is stored as floridean starch which is very similar to amylopectin and glycogen in structure. The red algae usually reproduce vegetatively by fragmentation. They reproduce asexually by non-motile spores and sexually by non-motilegametes. Sexual reproduction is oogamous and accompanied by complex  post fertilisation developments. The common members are: Polysiphonia, Porphyra , Gracilaria and Gelidium.