BIO 1040 CH. 3 QUESTIONS AND ANSWERS
LATEST UPDATE
What structures are found in all living cells?
cell membrane, cytoplasm, ribosomes, and DNA
What are the differences between prokaryotic and eukaryotic cells?
Eukaryotic cells contain a variety of membrane-enclosed organelles; prokaryotic cells
do not. (Eukaryotic cells have a nucleus)
Prokaryotic Cells
cells that lack internal membrane-bound organelles
Eukaryotic Cells
Cells that contain membrane-bound organelles, including a central nucleus
What is the function of the cell wall in bacteria?
The cell wall in bacteria allows bacteria to survive in watery environments- say, the
intestines, blood, or a pond
What is the function of the cell membrane?
-Isolate the cytoplasm from the external environment
-Regulate the exchange of substances
-Communicate with other cells
-Identification
What is the structure of the cell membrane?
Phospholipids make up the basic structure of a cell membrane. A single phospholipid
molecule has two different ends: a head and a tail. The head end contains a phosphate
group and is hydrophilic. This means that it likes or is attracted to water molecules.
Describe the phospholipid bilayer of the cell membrane?
The two layers of phospholipids arranged in such a way that their hydrophobic tails are
projecting inwards while their polar head groups are projecting on the outside surfaces
What substances can and cannot freely cross the semipermeable cell membrane?
Large molecules such as: glucose and hydrophilic substances like sodium ions.
What are the functions of proteins within cell membranes?
Transport proteins move molecules and ions across the membrane
Describe the following mechanisms of movement across cell membranes: simple
diffusion, facilitated diffusion, and active transport
Simple Diffusion - water, oxygen and other molecules move from areas of high
concentration to areas of low concentration, down a concentration gradient
Facilitated Diffusion - diffusion that is assisted by proteins (channel or carrier proteins)
Active Transport- involves moving molecules "uphill" against the concentration gradient,
which requires energy (ATP)
What is osmosis?
the diffusion of water across a semipermeable membrane from an area of lower solute
concentration to an area of higher solute concentration
What is the difference between hypotonic, isotonic, and hypertonic?
LATEST UPDATE
What structures are found in all living cells?
cell membrane, cytoplasm, ribosomes, and DNA
What are the differences between prokaryotic and eukaryotic cells?
Eukaryotic cells contain a variety of membrane-enclosed organelles; prokaryotic cells
do not. (Eukaryotic cells have a nucleus)
Prokaryotic Cells
cells that lack internal membrane-bound organelles
Eukaryotic Cells
Cells that contain membrane-bound organelles, including a central nucleus
What is the function of the cell wall in bacteria?
The cell wall in bacteria allows bacteria to survive in watery environments- say, the
intestines, blood, or a pond
What is the function of the cell membrane?
-Isolate the cytoplasm from the external environment
-Regulate the exchange of substances
-Communicate with other cells
-Identification
What is the structure of the cell membrane?
Phospholipids make up the basic structure of a cell membrane. A single phospholipid
molecule has two different ends: a head and a tail. The head end contains a phosphate
group and is hydrophilic. This means that it likes or is attracted to water molecules.
Describe the phospholipid bilayer of the cell membrane?
The two layers of phospholipids arranged in such a way that their hydrophobic tails are
projecting inwards while their polar head groups are projecting on the outside surfaces
What substances can and cannot freely cross the semipermeable cell membrane?
Large molecules such as: glucose and hydrophilic substances like sodium ions.
What are the functions of proteins within cell membranes?
Transport proteins move molecules and ions across the membrane
Describe the following mechanisms of movement across cell membranes: simple
diffusion, facilitated diffusion, and active transport
Simple Diffusion - water, oxygen and other molecules move from areas of high
concentration to areas of low concentration, down a concentration gradient
Facilitated Diffusion - diffusion that is assisted by proteins (channel or carrier proteins)
Active Transport- involves moving molecules "uphill" against the concentration gradient,
which requires energy (ATP)
What is osmosis?
the diffusion of water across a semipermeable membrane from an area of lower solute
concentration to an area of higher solute concentration
What is the difference between hypotonic, isotonic, and hypertonic?
