Gain-of-function mutations and Loss-of-function mutations

Gain-of-function mutations is defined as mutation that results in new or increased protein function. Gain of function mutations are dominant as one copy in a heterozygote can alter the normal phenotype. Loss-of-function mutations is defined as mutations that results in reduced activity on protein. Loss of function mutations are recessive as one copy in heterozygote […]

Eukaryotic cells express different genes at the same time

Eukaryotic cells express different genes at the same time because the gene contain same response elements in their regulatory promoters, all of which bind the same transcription activator. The genes expressed at same time must have same regulatory element sequence in promoters and transcription factors or activators bind to the regulatory elements so that genes […]

Origin of replication

The origin of replication is a sequence in DNA at which initiation of replication occurs. DNA has 4 nitrogen bases which are Adenine(A) , Guanine(G) , Thymine(T) , Cytosine(C). RNA also has 4 bases but in RNA Uracil (U) is present instead thymine. Adenine always pair with thymine by two hydrogen bonds in DNA. Guanine […]

Alternative splicing

Alternative splicing — single gene result in different proteins. Alternative or differential splicing is RNA splicing that produces multiple proteins from single gene during gene expression. Different Mechanisms Of Alternative Splicing: 1. Skipping of Exons: Exons are coding sequences that are joined with each other by covalent bonding and produces mature mRNA. Transcription of mRNAs […]

Adenosine Triphosphate (ATP)

ATP (Adenosine Triphosphate) consists of adenosine which is composed of adenine ring and a ribose sugar. It also contains three phosphate groups called as triphosphate. The phosphoryl groups named as alpha (α), beta (β), and gamma (γ) phosphates. It is named according to ribose sugar such as alpha (α) closest to ribose and gamma (γ) […]

Sickle Cell Anemia

Sickle cell anemia is a disease that contains abnormal hemoglobin which means sickle hemoglobin. It affects red blood cells (RBC) as it causes the cells in a sickle shape. Red blood cells are also called as erythrocytes that carry oxygen from lungs to rest of the body. Hemoglobin is the protein made by red blood […]

What are introns and exons?

Introns and exons are nucleotide sequences that carry genetic information within a gene. Introns are non-coding sequences and are removed by RNA splicing. Therefore introns are not expressed in the final mRNA product. If introns are not removed then final mRNA product contain extra sequence that leads to production of wrong protein during translation. Introns […]