Chapter 3: Cell Biology (Cell Structure)

Question 1

state the composition and function(2) of: the plasma/cell membrane

Answer 1

composition:
phospholipid bilayer with embedded proteins
function:
defines cell boundary; regulates molecule passage into and out of the cell

Question 2

state the composition and function of: mitochondria

Answer 2

composition: 
inner membrane (cristae) bounded by an outer membrane, eukaryotic membranous organelle
function: 
cellular respiration, breakdown of carbohydrates to produce ATP molecules

Question 3

state the composition and function of: endoplasmic reticulum

Answer 3

composition:
complicated system of membranous flattened channels, tubular canals, and sacs
function:
synthesis and/or modification of proteins and other substances, and distribution by vesicle formation

Question 4

state the composition and function of: smooth ER

Answer 4

composition:
network of folded membranes having no ribosomes
function:
various functions; lipid synthesis in some cells

Question 5

state the composition and function of: rough ER

Answer 5

composition:
network of folded membranes studded with ribosomes
function:
folding, modification, and transport of proteins

Question 6

state the composition and function of: ribosomes

Answer 6

composition:
protein and RNA in two subunits
function:
responsible for synthesis of proteins using mRNA template

Question 7

state the composition and function of: Golgi apparatus

Answer 7

composition:
stack of small membranous sacs
function:
shipping centre of the cell that collects, processes, packages and distributes materials such as proteins and lipids

Question 8

state the composition and function of: vesicles

Answer 8

composition:
tiny membranous sacs within endomembrane system of a cell
function:
storage and transportation of substances

Question 9

state the composition and function of: vacuoles

Answer 9

composition:
large membranous sacs found within cells
function:
storage of substances

Question 10

state the composition and function of: lysosomes

Answer 10

composition:
membrane-bound vesicles produced by Golgi apparatus; contains hydrolytic digestive enzymes
function:
intracellular digestion

Question 11

state the composition and function of: nuclear envelope

Answer 11

composition:
double membrane
function:
separate nucleus from cytoplasm in the cell

Question 12

state the composition and function of: nucleus

Answer 12

composition:
nuclear envelope, nucleoplasm, chromatin, and nucleoli
function:
storage of genetic information; synthesis of DNA and RNA

Question 13

state the composition and function of: nucleolus/nucleoli

Answer 13

composition:
concentrated areas of chromatin, RNA, and proteins
function:
where rRNA is produced and joins with proteins to form subunits of ribosomes

Question 14

state the composition and function of: chromosomes

Answer 14

composition:
highly condensed structures of coiled chromatin
function:
present when cell is ready to undergo cell division

Question 15

describe the functional interrelationships of the following cell structures: ribosomes, endoplasmic reticulum, transport vesicles, Golgi body, cell membrane

Answer 15

The ribosome, on the rough endoplasmic reticulum, produces proteins. The proteins are then packaged into transport vesicles and sent to the Golgi body. At the Golgi body, the proteins are sorted and repackaged into secretory vesicles, which head to the cell membrane. The proteins are secreted from the cell through exocytosis.

Question 16

describe the functional interrelationships of the following cell structures: vesicles, cell membrane, lysosome, Golgi body

Answer 16

A vesicle forms as a result of the invagination of the cell membrane. In the cytoplasm, the vesicle fuses with a lysosome that is produced by the Golgi body. The hydrolytic enzymes of the lysosome break down the contents of the vesicle.