Leys Exam 4 Protein Sorting

Question 1

Proteins that have ________ are no longer topologically inside the cell. They must ______ to get back inside the cell

Answer 1

Proteins that have CROSSED A MEMBRANE are no longer topologically inside the cell. They must RECROSS THE MEMBRANE to get back inside the cell

Question 2

Vesicles move from compartment to compartment within a cell by _____ and _____

Answer 2

Vesicles move from compartment to compartment within a cell by BUDDING OFF and MEMBRANE FUSION

Question 3

Many proteins have signal sequences at their ______ that direct the proteins to cross the membrane. Fewer proteins have _____ signal sequences.

Answer 3

Many proteins have signal sequences at their AMINO TERMINUS that direct proteins to cross the membrane. Fewer proteins have INTERNAL signal sequences.

Question 4

The nucleus is surrounded by a ________, however nuclear pores allow _______ to pass from the cytosol into the nucleus and back

Answer 4

The nucleus is surrounded by a DOUBLE LIPID MEMBRANE BILAYER, however nuclear pores allow MOLECULES (INCLUDING PROTEINS) to pass from the cytosol to the nucleus and back

Question 5

Proteins enter _____ using a mechanism similar to mitochondrial entry

Answer 5

Proteins enter PEROXISOMES using a mechanism similar to mitochondrial entry

Question 6

_______ bind to nuclear transport signals found on some nuclear bound proteins and _______ into the nucleus

Answer 6

NUCLEAR IMPORT RECEPTORS bind nuclear transport signals found on some nuclear bound proteins and FACILITATE TRANSPORT into the nucleus

Question 7

Proteins bound for the mitochondria are ________ in the cytosol and then transported through the ___________. A process that requires _____.

Answer 7

Proteins bound for the mitochondria are TRANSLATED in the cytosol and the transported through the MITOCHONDRIAL MEMBRANE. A process that requires ATP.

Question 8

The “default pathway” if there are no other signals directing the protein to other locations is to _________

Answer 8

The “default pathway” if there is no other signals directing the protein to other locations is to SEND THE PROTEIN TO THE CELL SURFACE

Question 9

Larger proteins pass through nuclear pores by an _______

Answer 9

Larger proteins pass through the nuclear pores by an ACTIVE PROCESS

Question 10

_________ modification of proteins in the ____ helps direct them to their ultimate location.

Answer 10

CARBOHYDRATE modification of proteins in the ER helps direct them to their ultimate location

Question 11

There are multiple protein ______ in the mitochondrial membrane. Each interacts with a specific ______.

Answer 11

There are multiple protein TRANSLOCATORS in the mitochondrial membrane. Each interacts with a specific SET OF PROTEINS.

Question 12

Proteins travel from the ____ through the ____ to many sites

Answer 12

Proteins travel from the ER through the GOLGI to many sites

Question 13

Transport of protein into the mitochondria requires _______.

Answer 13

Transport of protein into the mitochondria requires ENERGY.

Question 14

Proteins that are headed into or through the ER are transported through the _____ during _______. This process (does/does not) require additional energy.

Answer 14

Proteins that are headed into or through the ER are transported through the ER MEMBRANE during TRANSLATION. This process DOES NOT require additional energy.

Question 15

A ______ binds to the signal sequence during translation and directs the _____ to the ER membrane

Answer 15

A SIGNAL RECOGNITION PROTEIN (SRP) binds to the signal sequence during translation and directs the NASCENT PEPTIDE to the ER membrane.

Question 16

In regulated secretory pathway cells store proteins in _______ until they are signaled to release them from the cell by _______ with the cellular membrane

Answer 16

In regulated secretory pathway cells store proteins in SECRETORY VESICLES until they are signaled to release them from the cel by FUSION OF THE VESICLES with the cellular membrane.