BIO 110 Lecture Exam 2

Animal cells that had been growing in an incubator at 37 degrees C are suddenly cooled to 20 degrees C. In response to being cooled, what is most likely to happen?

Initially, the plasma membrane of the cells becomes less fluid.

Are plant cell walls chemically similar to prokaryotic cell walls? How are they the same or different?

No. Plant cell walls are made of cellulose and bacterial cell walls are made of peptidoglycans.

What characteristic do red blood cells have that led Evert Gorter to use them in his experiment?

- they are easy to count under a microscope - they are easy to obtain from animals - they can be obtained in large quantities from a single animal without harming it - all the red blood cells within an organism are the same size

What best describes the nature of the nuclear membrane?

A double phospholipid bilayer

What are actin filaments a part of? A) the endomembrane network B) the cytoskeleton C) the extracellular matrix D) none of the above

I answered A and got it wrong. I think it's actually C.

What is most likely true of phospholipids that will become part of a eukaryotic cell's plasma membrane? A) They are synthesized in the SER and placed into the plasma membrane by endocytosis. B) They are synthesized in the RER and placed into the plasma membrane by endocytosis. C) They are synthesized in the SER and placed into the plasma membrane by exocytosis. D) They are synthesized in the RER and placed into the plasma membrane by exocytosis. E) More information is needed.

I answered A but got it wrong. I think it's actually C.

Histones are proteins that bind to chromosomal DNA in the nucleus. Based on that knowledge, which of the following is true? A) Histone proteins will be synthesized by ribosomes associated with RER. B) Histone proteins will be synthesized by ribosomes within the nucleus. C) Histone proteins will be synthesized by ribosomes in the cytoplasm and not associated with the RER. D) Histone proteins will be synthesized by ribosomes within the lysosomes. E) More information is needed.

I answered B but got it wrong. I don't know what it actually is.

ATPase is an enzyme complex made out of many individual proteins. ATPase generates ATP in the mitochondria of eukaryotic cells. Based on that knowledge, which of the following is true about the proteins that the ATPase enzyme is made out of? A) they are synthesized by ribosomes associated with the RER B) they are synthesized by ribosomes within the nucleus C) they are synthesized by ribosomes in the cytoplasm and not associated with the RER D) more information is needed

I answered C but got it wrong. I don't know what the answer actually is.

Where precisely are ribosomes assembled in eukaryotic cells? A) the golgi B) the RER C) the nucleus D) the nucleolus

I answered C but got it wrong. I think it's actually D.

Within the chloroplast there is a thick liquid called: A) the cytoplasm B) the nucleoplasm C) the stroma D) the lumen

I answered D but got it wrong. It's actually C.

All prokaryotic and eukaryotic cells have the following except: A) organelles B) a plasma membrane C) genetic material D) a cell wall

I answered E but I got it wrong. I think E is actually right but they graded it wrong.

Which of the following is true of secondary lysosomes? A) they are released from the trans face of the golgi B) they can fuse with endocytic vesicles C) they can fuse with defective organelles D) they contain enzymes that hydrolyze polymers E) all of the above are true

I answered E but got it wrong, I think it's actually A.

Which of the following are in contact with the plasma membrane? A) the extracellular matrix B) the cytoskeleton C) integral proteins D) all of the above E) A and B

I answered E but got it wrong. I'm pretty sure it's actually C.

Animal cells that had been growing in an incubator at 37 degrees C are suddenly cooled to 20 degrees C. In response to being cooled, what is most likely to happen?

The cells will generate plasma membrane phospholipids with fatty acid chains that have more unsaturations

Animal cells that had been growing in an incubator at 37 degrees C are suddenly cooled to 20 degrees C. In response to being cooled, what is most likely to happen?

The cells will generate plasma membrane phospholipids with shorter fatty acid chains.

One unique characteristic of eukaryotic cells is the presence of __________>

a membrane-bound nucleus

What is true of membrane fluidity?

fluidity can be regulated by varying the length and degree of saturation in the fatty acid chains of membrane phospholipids

As the radius of a spherical cell __________, its volume increases __________ than its surface area and the ability to successfully support its metabolism __________.

increases, more quickly than, decreases

What do simple and facilitated diffusion have in common?

neither require the expenditure of cellular energy

Lipid bilayer membranes (LBMs) are more permeable to some types of molecules than others. What is the correct order of molecules that LBMs are permeable to starting with molecules the LBMs are most permeable to least permeable to?

non-polar molecules, small polar molecules, ions

All cells fall into 2 broad categories. What are they?

prokaryotes and eukaryotes

To be considered alive, an organism must be able to...

reproduce and grow/metabolize

The cell fusion experiment we did discussed what?

the fluid mosaic model of plasma membranes

The photo-bleaching experiments we discussed in class demonstrated...

the fluid mosaic of plasma membranes

A symporter is a carrier protein that...

transports two different molecular species in the same direction at the same time