Biology Now, 2e

Engineering Life ■ 75

(^4) Link each structure with the correct function.
CHLOROPLAST
GOLGI APPARATUS
LYS O S O M E

1. Location of the cell’s DNA.


2. Site of protein synthesis.


3. Site of lipid synthesis.

MITOCHONDRION

NUCLEUS

ROUGH ENDOPLASMIC

RETICULUM

SMOOTH ENDOPLASMIC

RETICULUM

4. Adds chemical tags to newly
   synthesized proteins to direct them
   to their correct location.


5. Breaks down biomolecules by
   enzymatic action.


6. Site of cellular respiration.


7. S i t e o f p h o t o s y n t h e s i s.

(^5) In the table below, indicate whether the specified cellular
component is found in each type of cell by placing an “X” in the
relevant columns.
Component Prokaryotes
Eukaryotes
Animals Plants
Plasma membrane
Cellulose cell wall
Nucleus
Endoplasmic reticulum
Golgi apparatus
Ribosomes
Cytoskeleton
Mitochondria
Chloroplasts
Challenge Yourself
(^6) How does the phospholipid bilayer of a liposome
differ from the phospholipid bilayer of the plasma membrane
of a cell?
(a) The phospholipid bilayer of a liposome contains only
phospholipids, without the proteins that are embedded in the
plasma membrane of a cell.
(b) The phospholipid bilayer of a liposome contains two bilayers
of phospholipid molecules, whereas the plasma membrane of a
cell contains only one.
(c) The phospholipid bilayer of a liposome completely envelops
the liposome, whereas the plasma membrane of a cell does not
completely envelop the cell.
(d) The phospholipid molecules in the phospholipid bilayer
of a liposome are oriented with the lipid ends on the
outside of the bilayer and the phosphate groups on
the inside.
be used by the cell. Plant vacuoles are similar to lysosomes but
also store ions and molecules and lend physical support to plant
cells.
● (^) Mitochondria produce chemical energy for eukaryotic cells in the
form of ATP.
● (^) Chloroplasts harness the energy of sunlight to make sugars
through photosynthesis.
● (^) Eukaryotic cells depend on the cytoskeleton for structural support
and for the ability to move and change shape. Plants and fungi also
have a cell wall that provides structural support.

THE QUESTIONS

The Basics

(^1) To be able to recognize a colony of bacteria that had grown
from cells of Mycoplasma capricolum in which the DNA had been
replaced by a synthetic DNA of Mycoplasma mycoides, Daniel
Gibson added a that coded for a blue pigment.
(a) cell
(b) chromosome
(c) gene
(d) bacterium
(^2) A phospholipid is a biomolecule composed of a
phosphate group that is bonded to two lipid chains. Which
of the following correctly describes the nature of those
two components?
(a) The phosphate group is hydrophobic, and the lipid chains are
hydrophilic.
(b) Both the phosphate group and the lipid chains are
hydrophilic.
(c) Both the phosphate group and the lipid chains are hydrophobic.
(d) The phosphate group is hydrophilic, and the lipid chains are
hydrophobic.
(^3) Link each process with the correct definition.
RECEPTOR-
MEDIATED
ENDOCYTOSIS
PHAGOCYTOSIS
PINOCYTOSIS
EXOCYTOSIS

1. A cell ingests a large particle, such as a
   bacterial cell.


2. Receptor proteins embedded in the membrane
   recognize specific surface characteristics of
   substances.


3. A transport vesicle inside the cell approaches the
   plasma membrane of the cell, fuses with it, and
   releases its contents to the outside of the cell.


4. A vesicle containing whatever molecules are in
   solution outside the cell bulges inward, pinches
   off, and enters the cell.