BIO EXAM 2

If a mutation blocked the function of the signal recognition particle, making it unable to bind signal sequence, what would You result?

All Proteins would be translated on free ribosomes in the cytoplasm

Which factors are used during translation?

All correct -elongation factors -release factors -initiation factors

Where are the ribosomes that translate proteins to be secreted from the cell?

Attached to the rough endoplasmic reticulum

Which of the statements is true regarding GLYCINE?

Glycine increases the flexibility of the peptide backbone

Enzymes present in the lumen of the Golgi apparatus are responsible for modifying proteins and lipids. Where must these proteins have been before they entered the Golgi apparatus?

In the rough end ppl admit reticulum

Which of the ribosomal sites does the anticodon of a tRNA pair completely with the mRNA codon?

A & P SITE

In response to seasonal changes in temperature many organisms must alter the composition of their plasma membranes to maintain the proper degree of fluidity. Which change in the fatty acids of phospholipids would be MOST effective in maintaining membrane fluidity in a colder environment?

A DECREASE in phospholipid fatty acid side chain length and a DECREASE in side chain saturation

During the translation of mRNA molecules..new polypeptides -EXPECT TO FIND IN POLYPEPTIDE THAT WILL FOLD TO BECOME A HISTONE PROTEIN?

A NUCLEAR localization signal

Disorders of which organelle are often associated with defects in transport from compartment to compartment resulting in poor sorting of protein components within the cell

THE GOLGI APPARTUS

All Polypeptides have tertiary structure

TRUE

The sequence of amino acids in a protein is referred to as its primary structure

TRUE

The codons in mRNA specify the amino acids that are used to make a protein TRUE/FALSE

TRUE -some 1 codons others by multple codons

A protein with an internal signal sequence is most likely to be located in:

The NUCLEUS

Which part of a cholesterol molecule is polar?

The OH GROUP

FRAP EXPERIMENT

The bleached spot will NOT recover fluorescence over time

#36 animation translation elongation what's the anticodon of the next tRNA to enter the A site

*look a P site rna template bottom -middle to right Remember antiparrel A: 3' CUU5'

What will happen when the ribosome shifts one codon further on the mRNA assuming the next codon is not a stop codon? Select all that apply

-A new tRNA will bind to the ribosome -tRNA Carrying the polypeptide will be in the P site -The tRNA that is no longer carrying the polypeptide will be ejected from the ribosome

A proton pump is needed in the lysosomal membrane because

-the interior of the lysome needs to be acidic -protons cannot move across a membrane on their own -protons are being moved from low to high concentration All These Choices Are Correct

Referrring to 5' -AUGAGACUUACCGAA-3' what would the anticodon look like if the 2nd nucleotide of the fourth codon was muted to U

3'—UAG—5' 4th codon is 5'—ACC—3' will change to 5'—AUC—3' the anticodon complementary and antiparallel to this codon will be 3'—UAG—5'

How many different mRNA sequences could encode the amino acid sequence Met-Leu-Val-His?

48 There's 1 codon for Met 6 for Leu 4 for Val 2 for His 1*6*4*2=48

#19

5'-AUGAUCGGAUCGAUCCAU-3'

During translation of mRNA molecules new polypeptides-WOULD FOLD TO RNA POLYMERASE

A nuclear localization signal

Which of the environmental factors affect the interactions between amino acids that in turn determine the shape of a protein?

All of the choices are correct -pH -ion concentration -temperature -hydrophilic or hydrophobic properties of the environment -temperature and ion concentration

Some diseases result from defective transport across the membrane. For example, cystic fibrosis results when a chloride ion transporter does not function. What is affected when this transporter does not function?

BOTH the chloride concentration gradient and the electrical gradient of the cell

Mitochondria and chloroplasts are intergral parts of the embrace system and are specifically connected to the endoplasmic reticulum

FALSE -mitochondria and chloroplasts aren't connected to the embrace system

Assuming that transcription and translation both proceed from left to right what is correct DNA, RNA, protein product

DNA: 3'.........5' RNA: 5'...........3' Protein product: H2N—.........-COOH

The beaker in the illustration below contains two solutions of salt with different concentrations (measured by molarity, M). The two solutions are separated by a membrane that is permeable to both salt and water.

Diffusion of water from A to B but no diffusion of salt

Which one is responsible for addition of amino acids after translation initiation has begun?

ELONGATION FACTORS

All 64 possible codons have corresponding anticodons in tRNAs

FALSE

All B sheets are compromised of protein strands running antiparallel to each other

FALSE

Most proteins retain metabolic activity when denatured

FALSE

Purified phospholipids mixed in water will only form membranes if the appropriate enzyme is present

FALSE

A researcher has devised a technique that allows her to label all the intergral membrane proteins with a fluorescent tag. She uses a laser to bleach the fluorescene in a specific area of the cell membrane. After 24 hours she notices that flourecense has returned to the bleach are. What can she deduce from this experiment?

Integral membrane proteins are able to move laterally within the cell membrane consider how intergral membrane proteins that were not bleached at the start of the experiment might be able to return to the previously bleached area by lateral movement in the fluid mosaic of the membrane

Individuals with a condition known as excel use intolerance lack sufficient ATP and suffer extreme fatigue from minimal extortion-DEFECTS IN THIS STRUCTURE

MITOCHONDRIA

Which particles are pumped across the lysosomal membrane by a transport protein to create a special internal environment in the lysosome ?

PROTONS -lys enyzymes become fully functional in a acidic environment with a low pH and high concentration of protons

Which is more likely to form a micelle rather than a liposome if mixed in an aqueous environment?

Phospholipids with a SINGLE fatty acid Tail

Big chart with stop codons

Polylysine terminated by a Thr (look at question to understand)

Where are lysosomal enyzymes synthesized?

on the rough endoplasmic reticulum to end up inside a lysosome a protein needs to be synthesized in association with the ER

What would be synthesized on the rough endoplasmic reticulum?

transmembrane protein receptors proteins synthesized in the rough endoplasmic reticulum are either moved through membranes into organelles or are transmembrane proteins