Card Set Information
Gene Expression: From Genes to Proteins
DNA is translated into proteins, the intermediary between ____ and _____
Phenotypes of what, all result from protein function
cells, tissues, and organisms
The sequence of nucleotides in our DNA encodes....
1. the proteins we produce
2. how much of each is expressed in a given cell
The amount of information stored in a cell is related to....
the number of nucleotides within that cell
genes are made up of....
Proteins are made-up of....
20 amino acids
Direct relationship of nucleotides to amino acids is...
The information to encode a single amino acid is carried in a sequence of how many nucleotides
3 nucleotides give 4*3 different combinations to encode the....
20 amino acids
Each triplet is called a what
How is the linear sequence of nucleotides in a gene converted into the linear sequence of amino acids in a protein
1. DNA is in the nucleus
2. proteins are synthesized in the cytoplasm
3. information transfer must be indirect... via RNA
, genetic information is copied into mRNA in the what?
2. The information within the mRNA is then translated from ____ to ____ in the cytoplasm during
*End result is a phenotype
2. nucleotide, amino acid
The process of transcription
1. RNA polymerase binds DNA at the gene's promoter (the DNA helix unwinds)
2. initiation of transcription (RNA synthesis begins)
3. elongation: pairing up (a-u)
4. Termination when RNApol reaches terminator region
*In eukaryotic cells there is on more step= RNA processing
Heterogeneous Nuclear RNA
Newly synthesized RNA; must be modified before it is fully functional
Nucleotides that are transcribed, but not translated (noncoding sequences)
1. Caps are added for initiation of translation and stability
2. a poly adenine tall is also added
introns are removed
Transcriptional Regulation of Genes
*mature mRNA transcripts are released into the cytoplasm through pores in the nuclear envelope
*highly regulated process:
1. initiation of transcription
3. nuclear export
Translation into Amino Acids
*The nucleic acid code in the mRNA is
into amino acids to synthesize polypeptides
All 20 amino acids have 3 characteristic groups
1. an amino group (NH2)
2. a carboxyl group (COOH)
3. a unique side chain ( R)
During protein synthesis, amino acids are linked by the formation of....
A dipeptide contains how many amino acids
2 (10+ form a polypeptide)
Polypeptides are read from....
Their N-terminus to the C-terminus
How can four nucleotides code for 20 amino acids
They have to have 3 nucleotides at a time
The number/sequence of bases in a gene determines....
the information that it carries
In eukaryotes, mature mRNA is exported out of the nucleus into the cytoplasm where it is translated by...
There are 4 stages in protein synthesis
1. initiation- requires amino acids, tRNA's and energy
4. Termination- Elongation ceases once a STOP codon is reached; the complex falls off
After a polypeptide is formed, it folds into a 3D shape determined by...
its amino acid sequence
Polypeptide folding is guided by proteins called
The process in which polypeptides can be chemically modified after they are created is called...
Once a polypeptide is folded, modified, and sometimes complexed with other polypeptides, a functional____ is formed
Four levels of Protein structure
linear amino acid sequence in polypeptide chain
3D configurations that result from interactions between amino acids' NH and CO groups
: folding of secondary structure back on itself
: interactions between two or more polypeptide chains
Protein refolding diseases are called...
protein folded into an infectious conformation that is the cause of several disorders
1. catalyze biochemical reactions and accelerate reaction rates
2. They sequester substrates in their active site, providing the proper environment for the reaction to occur rapidly and with relatively little energy
3. without enzymes, most chemical reactions in our body would take longer than our lifespan to complete