chaoter 2 biology 11

if rRNA directs the formation of ribosomes, then what is the job of mRNA?

mRNA leaves the nucleus and attach to the ribosomes, where its information is used to form a protein.

What is a “selectively permeable membrane”

A barrier that allows some molecules to pass through, but prevents other molecules from penetrating.

In what specific kinds of human cells is the selectively permeable membrane especially important in helping control what goes in and out of the cell in a carefully controlled manner.

In the nervous, intestinal, and kidney tissues.

Of DNA or RNA , which one is single stranded?

RNA

Lipids are a chemical group that includes :

fats and oils

Both flagella and cilia both use what kind of protein to enable them to spin, whip or wave back in forth.

Contractile proteins

Other then the nucleus , what is the largest of the animal cell organelles in the cytoplasm

Mitochondria

The mitochondrial cristae provide more space for cellular respiration to occur . What kind of proteins are attached to the cristae to speed this process up?

Enzymes

What is unique about mitochondrial DNA? What is the theory about why that is?

Mitochondria constrain their own dna, unlike that in the nucleus. The theory is that the mitochondria were once separate organisms that invaded eukaryotic cells.

In a normal cell, any disruption of the function of the mitochondria will cause the cell to die. How does this result differ in cancerous tumour cells.

In tumour cells, the abnormal mitochondria allows the cells to continue to live and grow.