Lecture 4: Gene Regulation

Question 1

Proteins

Answer 1

• building blocks are amino acids that have R groups, amino groups, and a carboxyl group
• AA differs in R-Groups- unique behavior
• mRNA translated from 5’ to 3’ protein is synthesized from the amino end (N-terminus) to the carboxy end (C-terminus)

Question 2

Primary Proteins

Answer 2

Sequence of a chain of amino acids connected by peptide bond

Question 3

Second Proteins

Answer 3

Sequence of amino acids that are linked by weak hydrogen bonds into one or two structural forms

Question 4

Tertiary Proteins

Answer 4

a 3D structure produced from alpha helixes and beta helixes attractions

Question 5

Functions of Proteins

Answer 5

They are catalysts, transporting and storing molecules, provide mechanical support and immune protection, generates movements, transmit nerve impulses, and control cell growth and differentiation

Question 6

Post Translational Modifications

Answer 6

Hydroxylation, methylation, lipidation, acetylation, phosphorylation, glycosylation, ubiquitination, disulfide bond, and SUMOylation

Question 7

Mutations

Answer 7

Changes in nucleotide sequence of DNA and can occur spontaneously as errors during DNA replication or caused by environmental agents. It is the major cause of genetic diversity and disease. In bioprocessing, mutations can affect the production levels and quality of protein production. Insertion or deletion of 3 nucleotides causes no extensive frameshift.

Question 8

Point Mutations

Answer 8

Consists of one DNA base change
ex: silent mutation, missense mutation, and nonsense mutation

Question 9

Silent Mutation

Answer 9

No effect on the amino acid sequence- base pair substitution

Question 10

Missense Mutation

Answer 10

Changes in amino acid coded for
ex: sickle cell anemia which reduces the oxygen-carrying capacity of RBC is due to missense mutation in one of the hemoglobin peptides

Question 11

Nonsense Mutation

Answer 11

Creates stop codon

Question 12

Deletion

Answer 12

Frameshift causing extensive missense

Question 13

Insertion

Answer 13

Frameshift causing immediate nonsense

Question 14

Promoters

Answer 14

DNA sequence found 5’ upstream of gene sequences to which RNA polymerase binds to initiation transcription. Activation of promoters => amount of mRNA.

Question 15

Operons

Answer 15

Regulate gene expression in response to their nutrient requirements, and other cell needs/processes. Operons are several genes located on after another, in the same direction.

Question 16

Operator

Answer 16

Region within promoter where transcriptional repressor protein binds. NOT FOUND IN EUKARYOTES.

Question 17

Activator Proteins

Answer 17

Promote expression of specific genes by binding to enhancer regions. It may require other non-protein inducers (testosterone, estrogen). In eukaryotes, the same activator proteins that bind to specific control elements can regulate multiple genes simultaneously.

Question 18

Epigenome

Answer 18

• Are modifications in chromatin that do not involve changes in DNA sequence. Some are heritable while some are not. Some or reversible and some persist longer. They can differ between tissue types: role in embryonic development and cancer cells.
• Chemical modifications can be in histones or on DNA

Question 19

Histones

Answer 19

Highly Alkaline proteins found in eukaryotic cell nuclei that package and order the DNA into structural units called nucleosomes