BIO130H1 Chapter : Pg. 721-727.docx

60 views1 pages

fuchsiamammoth394

11 Apr 2012

School

Department

Course

Professor

For unlimited access to Textbook Notes, a Class+ subscription is required.

ash-mr18 and 40043 others unlocked

BIO130H1 Full Course Notes

Verified Note

31 documents

Document Summary

Peroxisomes: can be used to break down harmful chemicals. Peroxisomes are major sites of oxygen utilization. It contains oxidative enzymes such as catalase and urate catalase. Peroxisomes use molecular oxygen and hydrogen peroxide to perform oxidation. Catalase can break down hydrogen peroxide into water and oxygen. This reaction can occur in liver cells. Peroxisomes are important in plants; one type is present in leaves: helps with photorespiration; the other type is present in germinating seeds: helps young plant grow. A short signal sequence directs the import of proteins into peroxisomes. Peroxins: 23 distinct proteins participate in importing the proteins. Human disease called zellwegger syndrome: defect in peroxisomes. Endoplasmic reticulum (er): labyrinth like branching tubules. Er lumen: space between the er and the nuclear membrane. Er contains co-translational process: import of proteins; ribosomes are attached translating the proteins; rough er. Mitochondrion, chloroplast, nuclei and peroxisome contain post-translational process: to import proteins; proteins are already translated.

Related Questions

Describe the chemical composition of each structures below. (Note that the chemical composition for many of the structures listed is a phospholipid bilayer.)

cell wall

chromatin

cytosol-

chloroplasts

chromoplasts

cytoskeleton

Golgi apparatus

leucoplasts

mitochondria

nuclear envelope

plasma membrane

peroxisomes

ribosomes

rough endoplasmic reticulum

smooth endoplasmic reticulum

tonoplast

raspberryreindeer434

I am attempting to build a list of proteins and their "Final destination in the cell" as well as "targeting sequence".

An example is Actin-cytosol-no targeting sequence

Voltage gated channel- cell membrane-multiple start stop

Peroxidase-peroxisomes-peroxisomal targeting sequence

Albuin-outside of the cell-N terminal

Histones-nucleus-nuclear localization signal

ATP synthase- mitochondira- mitochondial tageting sequenece

If you could please name 4 proteins for each sequence (No targeting sequence, multiple start-stop, N terminal ER Targeting sequence, nuclear targeting sequence, peroxisomal targeting sequence, and mitochondrial targeting sequenece.)

Thnak you in advance!

Imagine that you have engineered a set of genes , each encoding a protein with a pair of conflicting signal sequences that specificy different compartments. If the genes were expressed in a cell, what signal would win and why?

1) A) Signals for import into ER would beat signals for import int the nucleus. What is the reasonable explanation?

1) The nuclear transport receptor is more efficient than the signal recognition particle (SRP)

2) The ER signal near the N-terminus will be exposed before the nuclear signal during protein synthesis and thus recognized by SRP before the nuclear signal is even available

3) the nuclear signal near the middle of the sequence will be exposed before the ER signal during protein synthesis and thus recognized by the nuclear transprot protein before the ER signal is active.

4) the SRP is more efficient than the nuclear transport receptor.

B) Signals for import into ER would beat signals for import into peroxisomes. What is the reasonable explanation?

1) The peroxisome transport proteins are more efficient than the signal recognition particle (SRP)

2) The ER signal near the N-terminus will be exposed before the peroxisome signal during protein synthesis and thus recognized by SRP before the peroxisome signal is even available

3) peroxisome proteins are transported by vesicles not by transport proteins.

4) the SRP is more efficient than the peroxisome transporter.

C) Signals into the mitochondria and retention into the ER? Which would win? Reasonable explanation as to why?

1)Mitochondria

2)ER

and

1) The mitochondrial transport protein is more efficient than the signal recognition particle (SRP)

2) The ER signal near the N-terminus will be exposed before the mitochondrial signal during protein synthesis and thus recognized by SRP before the mitochondrial signal is even available

3) the mitochondrial signal near the N-terminus of the sequence will be exposed before the ER retention during protein synthesis and thus recognized by the SRP before the ER signal is active

4) the signal for retention of a protein in the ER is at the C-terminus and not recognized until import into the ER begins

rosesnail820

BIO130H1 Chapter : Pg. 721-727.docx

BIO130H1 Full Course Notes

Document Summary

Get access

Related textbook solutions

Molecular Cell Biology

Biology: Science for Life with Physiology

Concepts of Biology

Biology

Essentials of Biology

Related Documents

HIST10014 Lecture 4: BIOL10004 Lecture 4 Notes

ANP 1105 Lecture Notes - Lecture 4: Endoplasmic Reticulum, Golgi Apparatus, Nuclear Membrane

BIOLOGY 2B03 Lecture Notes - Lecture 8: Ubiquitin, Dominance (Genetics), Pex5

Related Questions