BIO 2// CH 3

The sodium-potassium pump requires a carrier protein that binds

3 sodium and 2 potassuim ions

How the nucleus originated?

A portion of the plasma membrane was internalized so that it surrounded the DNA within a cell.

Which scenario below most likely explains how the nucleus originated?

A portion of the plasma membrane was internalized so that it surrounded the DNA within a cell.

cell wall

A rigid layer of nonliving material that surrounds the cells of plants and some other organisms.

CELL

Basic unit of life

Place the following organelles of the endomembrane system in the order they are used in the synthesis, packaging, and the export of proteins.

Ribosomes on rough endoplasmic reticulum, transport vesicle, Golgi apparatus, secretory vesicle, plasma membrane

In addition to the nucleus, which of the following organelles are also thought to have evolved from an invagination of the plasma membrane?

The Golgi apparatus. The endoplasmic reticulum. Lysosomes.

How did early eukaryotic cells benefit from the aerobic bacteria that took up residence within them?

The aerobic bacteria metabolized sugars and generated large amounts of ATP.

How did early eukaryotic cells benefit from the photosynthetic bacteria that took up residence within them?

The aerobic bacteria were able to capture the sunlight and generate sugars from it.

Why are the organelles within the endomembrane system interchangeable?

They are all comprised of phospholipid membranes.

Which of the following statements is true in regards to the order and location of the movement of ions in the sodium-potassium pump?

Three sodium ions leave the cell, and then two potassium ions enter the cell.

If the contents of a beaker are isotonic in relation to the interior of the cell, water will

both enter and exit the cell at equal rates so no net loss or gain occurs.

A protein produced on a free ribosome has a different_____ a protein produced at an attached ribosome.

destinationthan

Ribosomes, composed of proteins and rRNA, are often found attached to the ____, but may also occur freely in the cytoplasm.

endoplasmic reticulum

If the contents of a beaker are hypotonic in relation to the interior of the cell, water will

enter the cell and lysis will occur.

If the contents of a beaker are hypertonic in relation to the interior of the cell, water will

exit the cell and crenation will occur.

After products leave the endoplasmic reticulum, they head to the ______ for further processing, modification, and repackaging.

golgi apparatus

Groups of free ribosomes are called ____

polyribosomes

Ribosomes are the site of

protein synthesis

Osmosis can best be described as

the diffusion of water from areas where the water concentration is higher to areas where the water concentration is lower.

Active transport can best be described as

the movement of molecules against their concentration gradient, from areas of lower concentration to areas of higher concentration.

The rough endoplasmic reticulum differs from the smooth endoplasmic reticulum in that

the rough endoplasmic reticulum contains ribosomes, while the smooth endoplasmic reticulum does not.the rough endoplasmic reticulum forms transport vesicles to aid in moving its products, while the smooth endoplasmic reticulum does not.the rough endoplasmic reticulum is mostly involved in protein synthesis, while the smooth endoplasmic reticulum is mostly involved in the production of lipids and carbohydrates.

Which of the following is responsible for determining which direction water will diffuse across the plasma membrane of cells?

tonicity