Test Unit 2: Cell Structure and Function

T or F; Prokaryotic cells have their DNA in a membrane bound, nucleoid region

False

T or F; Lysosomes are membranous sacs with hydrolytic enzymes that catalyze reactions that produce H202

False

The Calvin cycle occurs in the stroma of …

chloroplasts

T or F; Ribosomes assemble into large and small subunits, which together translate the messages found on mRNA into the primary structure of polypeptides

true

Inside of the chloroplast … are membranous sacs that can organize in stacks know as …

thylakoids; stroma

The Golgi contains flattened membraneous sacs called …

cistern

DNA is first transcribed into RNA in the nucleus

1st step

ribosomes on the rough ER translates the mRNA into proteins

2nd step

proteins are sent to the cis-face of the Golgi, where it is packaged and then sent out by the tans-face in vesicles, which is exocytosis.

3rd step

Compartmentalization in eukaryotic cells

helps separate reaction from interfering with one another and increases the surface area.

If there was a mutation to the gene that allows water to pass through plasma membranes via osmosis.

cells would still be able to uptake water, as water can pass through the cell membrane without the assistance of aquaporins. However, it would take up water a a much slower rate because water has a slight charge.

What characteristics are able to pass through the membrane the easiest?

Small, hydrophobic substances

Simple diffusion

small, uncharged polar molecules

Which of the following pieces of evidence best supports the endosymbiotic theory?

some organelles in eukaryotes have their own DNA similar to that of prokaryotes

How does the carrier protein return to its original positions to accept more sodium?

The phosphate group will detach, thus causing a conformational change

Phagocytosis

specialized form of endocytosis where cells, primarily immune cells like macrophages and neutrophils, engulf and destroy large particles

Which component of the plasma membrane plays an important role in the identification of other cells?

Glycoproteins

What does it mean to say that phospholipids are amphipathic?

They have both hydrophilic and hydrophobic parts

Which structure below is unable to imbed itself within the phospholipid bilayer?

Peripheral proteins

simple diffusion

small polar molecules

facilitated diffusion

large polar, charged molecules