Cell Physiology Exam Questions and Answers Fully Solved Graded A+
Define the basic structural and functional unit of life - Answers Cell
All living organism are composed of - Answers Cells
How many cells are in the human body? - Answers 50 to 100 trillion
What are the three main regions of the cell? - Answers Plasma Membrane, Cytoplasm, Nucleus
What is the thin and flexible membrane of the cell which separates the intracellular from extracellular
fluid? - Answers Plasma Membrane
What is another name for the Plasma Membrane - Answers plasmalemma
What are three things the membrane is composed of and what is embedded in the membrane? -
Answers Double layer of lipids; phospholipids, cholesterol, glycolipids; proteins are embedded
What is the most abundant lipid in the plasma membrane? - Answers phospholipids
The heads of phospoholipids are (Hydrophilic/hydrophobic) - Answers Hydrophilic
The tails of phospholipids are (Hydrophilic/hydrophobic) - Answers Hydrophobic
What are the two types of membrane proteins? - Answers Integral and Peripheral
What are the most abundant proteins in the membrane? (Most are transmembrane but some protrude
from one side of the membrane) could act as a receptor. - Answers Integral Proteins
What proteins are mostly on the cytoplasmic side and support that side by a network of filaments? -
Answers Peripheral Proteins
What is a short chain of carbohydrates (sugars) projected out from the external surface of glycoproteins
or glycolipids called? what is its function? - Answers Glycocalyx (Cell Coat); functions in cell to cell
binding and recognition
What cells produce Glycocalyx? - Answers Corneal epithelial surface cells
Three functions of the Plasma Membrane - Answers 1. Barrier against substances and forces outside cell
2. externally-facing proteins act as receptors and in cell to cell recognition
3. Acts in transport of substances into or out of cell
What type of barrier is the membrane considered? - Answers Selective permeable
What is the Passive Process of movement? - Answers Substances can pass freely through the lipid
bilayer down their concentration gradient. No ATP needed
, What is Diffusion? - Answers Movement of small uncharged molecules like oxygen, CO2, and fat soluble
molecules across the membrane
What is the Active Process of Movement? - Answers Substances move against their concentration
gradient from a lower to higher concentration. ATP is needed
What is Active Transport? - Answers Most larger water soluble or charged molecules, such as glucose,
amino acids, and ions are transported by a pump or carrier and involve the integral proteins
What is Vesicular or Bulk Transport? - Answers Large particles and macromolecules pass through the
membrane by this mechanism.
What are the two types of Bulk Transport? - Answers Exocytosis and Endocytosis
What is Exocytosis? - Answers Membrane-lined cytoplasmic vesicles fuse with the plasma membrane
and release their contents to the outside of the cell.
What is an example of Exocytosis? - Answers Mucus and Protein secretions from the glands in the body
What is Endocytosis? - Answers Brings large molecules into the cell, through an initial infolding part of
the plasma membrane that encloses them to form cytoplasmic vesicles. Clathrin Protein, found on the
cytoplasmic side of the infolding, is responsible for deforming the membrane.
What are the three types of Endocytosis? - Answers Phagocytosis, Pinocytosis, and Recptor-Mediated
Endocytosis
What is Phagocytosis? (AKA Cell Eating) - Answers A type of Endocytosis where parts of plasma
membrane form pseudopodes and flow around large molecules such as bacteria or cellular debris and
engulf it. By this way, a membranous vesicle, called a phagosome is formed.
What is the function of the Phagosome formed during Phagocytosis? - Answers Phagosomes mostly fuse
to the lysosomes for enzymatic breakdown of phagosomal contents. White Blood Cells typify such
phagocytotic activity.
What is Pinocytosis? (AKA Cell Drinking) - Answers Pinocytosis is fluid phase endocytosis, where a small
infolding of the plasma membrane surrounds a small quantity of ECF containing dissolved molecules.
This is the primary function of cells lining the small intestine, absorption of the nutrients.
What is Receptor-Mediated Endocytosis? - Answers Receptor-Mediated Endocytosis is a selective
mechanism. Specific molecules such as insulin and other hormones, enzymes, and LDLs are brought into
the cells by first attaching to a receptor on the membrane before being taken into the cells in a protein
coated vesicle. Contents are then released by binding to lysosomes and the receptors are recycled back
into the plasma membrane. Viruses and some toxins use the same mechanism to enter cells.
What are LDLs? - Answers Low Density Lipoproteins: Molecules that carry cholesterol in the blood to the
body's cells
Define the basic structural and functional unit of life - Answers Cell
All living organism are composed of - Answers Cells
How many cells are in the human body? - Answers 50 to 100 trillion
What are the three main regions of the cell? - Answers Plasma Membrane, Cytoplasm, Nucleus
What is the thin and flexible membrane of the cell which separates the intracellular from extracellular
fluid? - Answers Plasma Membrane
What is another name for the Plasma Membrane - Answers plasmalemma
What are three things the membrane is composed of and what is embedded in the membrane? -
Answers Double layer of lipids; phospholipids, cholesterol, glycolipids; proteins are embedded
What is the most abundant lipid in the plasma membrane? - Answers phospholipids
The heads of phospoholipids are (Hydrophilic/hydrophobic) - Answers Hydrophilic
The tails of phospholipids are (Hydrophilic/hydrophobic) - Answers Hydrophobic
What are the two types of membrane proteins? - Answers Integral and Peripheral
What are the most abundant proteins in the membrane? (Most are transmembrane but some protrude
from one side of the membrane) could act as a receptor. - Answers Integral Proteins
What proteins are mostly on the cytoplasmic side and support that side by a network of filaments? -
Answers Peripheral Proteins
What is a short chain of carbohydrates (sugars) projected out from the external surface of glycoproteins
or glycolipids called? what is its function? - Answers Glycocalyx (Cell Coat); functions in cell to cell
binding and recognition
What cells produce Glycocalyx? - Answers Corneal epithelial surface cells
Three functions of the Plasma Membrane - Answers 1. Barrier against substances and forces outside cell
2. externally-facing proteins act as receptors and in cell to cell recognition
3. Acts in transport of substances into or out of cell
What type of barrier is the membrane considered? - Answers Selective permeable
What is the Passive Process of movement? - Answers Substances can pass freely through the lipid
bilayer down their concentration gradient. No ATP needed
, What is Diffusion? - Answers Movement of small uncharged molecules like oxygen, CO2, and fat soluble
molecules across the membrane
What is the Active Process of Movement? - Answers Substances move against their concentration
gradient from a lower to higher concentration. ATP is needed
What is Active Transport? - Answers Most larger water soluble or charged molecules, such as glucose,
amino acids, and ions are transported by a pump or carrier and involve the integral proteins
What is Vesicular or Bulk Transport? - Answers Large particles and macromolecules pass through the
membrane by this mechanism.
What are the two types of Bulk Transport? - Answers Exocytosis and Endocytosis
What is Exocytosis? - Answers Membrane-lined cytoplasmic vesicles fuse with the plasma membrane
and release their contents to the outside of the cell.
What is an example of Exocytosis? - Answers Mucus and Protein secretions from the glands in the body
What is Endocytosis? - Answers Brings large molecules into the cell, through an initial infolding part of
the plasma membrane that encloses them to form cytoplasmic vesicles. Clathrin Protein, found on the
cytoplasmic side of the infolding, is responsible for deforming the membrane.
What are the three types of Endocytosis? - Answers Phagocytosis, Pinocytosis, and Recptor-Mediated
Endocytosis
What is Phagocytosis? (AKA Cell Eating) - Answers A type of Endocytosis where parts of plasma
membrane form pseudopodes and flow around large molecules such as bacteria or cellular debris and
engulf it. By this way, a membranous vesicle, called a phagosome is formed.
What is the function of the Phagosome formed during Phagocytosis? - Answers Phagosomes mostly fuse
to the lysosomes for enzymatic breakdown of phagosomal contents. White Blood Cells typify such
phagocytotic activity.
What is Pinocytosis? (AKA Cell Drinking) - Answers Pinocytosis is fluid phase endocytosis, where a small
infolding of the plasma membrane surrounds a small quantity of ECF containing dissolved molecules.
This is the primary function of cells lining the small intestine, absorption of the nutrients.
What is Receptor-Mediated Endocytosis? - Answers Receptor-Mediated Endocytosis is a selective
mechanism. Specific molecules such as insulin and other hormones, enzymes, and LDLs are brought into
the cells by first attaching to a receptor on the membrane before being taken into the cells in a protein
coated vesicle. Contents are then released by binding to lysosomes and the receptors are recycled back
into the plasma membrane. Viruses and some toxins use the same mechanism to enter cells.
What are LDLs? - Answers Low Density Lipoproteins: Molecules that carry cholesterol in the blood to the
body's cells
