Cell Physiology – End Term Exam | A+ Graded
Questions with Verified Answers
What is a short chain of carbohydrates (sugars) projected out from the external surface of
glycoproteins or glycolipids called? what is its function? - ✔✔Glycocalyx (Cell Coat); functions
in cell to cell binding and recognition
What cells produce Glycocalyx? - ✔✔Corneal epithelial surface cells
Three functions of the Plasma Membrane - ✔✔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? - ✔✔Selective permeable
What is the Passive Process of movement? - ✔✔Substances can pass freely through the lipid
bilayer down their concentration gradient. No ATP needed
What is Diffusion? - ✔✔Movement of small uncharged molecules like oxygen, CO2, and fat
soluble molecules across the membrane
What is the Active Process of Movement? - ✔✔Substances move against their concentration
gradient from a lower to higher concentration. ATP is needed
Define the basic structural and functional unit of life - ✔✔Cell
All living organism are composed of - ✔✔Cells
How many cells are in the human body? - ✔✔50 to 100 trillion
,What are the three main regions of the cell? - ✔✔Plasma Membrane, Cytoplasm, Nucleus
What is the thin and flexible membrane of the cell which separates the intracellular from
extracellular fluid? - ✔✔Plasma Membrane
What is another name for the Plasma Membrane - ✔✔plasmalemma
What are three things the membrane is composed of and what is embedded in the
membrane? - ✔✔Double layer of lipids; phospholipids, cholesterol, glycolipids; proteins are
embedded
What is the most abundant lipid in the plasma membrane? - ✔✔phospholipids
The heads of phospoholipids are (Hydrophilic/hydrophobic) - ✔✔Hydrophilic
The tails of phospholipids are (Hydrophilic/hydrophobic) - ✔✔Hydrophobic
What are the two types of membrane proteins? - ✔✔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. - ✔✔Integral Proteins
What proteins are mostly on the cytoplasmic side and support that side by a network of
filaments? - ✔✔Peripheral Proteins
What is Active Transport? - ✔✔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? - ✔✔Large particles and macromolecules pass through
the membrane by this mechanism.
, What are the two types of Bulk Transport? - ✔✔Exocytosis and Endocytosis
What is Exocytosis? - ✔✔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? - ✔✔Mucus and Protein secretions from the glands in the
body
What is Endocytosis? - ✔✔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? - ✔✔Phagocytosis, Pinocytosis, and Recptor-
Mediated Endocytosis
What is Phagocytosis? (AKA Cell Eating) - ✔✔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? - ✔✔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) - ✔✔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? - ✔✔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.
Questions with Verified Answers
What is a short chain of carbohydrates (sugars) projected out from the external surface of
glycoproteins or glycolipids called? what is its function? - ✔✔Glycocalyx (Cell Coat); functions
in cell to cell binding and recognition
What cells produce Glycocalyx? - ✔✔Corneal epithelial surface cells
Three functions of the Plasma Membrane - ✔✔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? - ✔✔Selective permeable
What is the Passive Process of movement? - ✔✔Substances can pass freely through the lipid
bilayer down their concentration gradient. No ATP needed
What is Diffusion? - ✔✔Movement of small uncharged molecules like oxygen, CO2, and fat
soluble molecules across the membrane
What is the Active Process of Movement? - ✔✔Substances move against their concentration
gradient from a lower to higher concentration. ATP is needed
Define the basic structural and functional unit of life - ✔✔Cell
All living organism are composed of - ✔✔Cells
How many cells are in the human body? - ✔✔50 to 100 trillion
,What are the three main regions of the cell? - ✔✔Plasma Membrane, Cytoplasm, Nucleus
What is the thin and flexible membrane of the cell which separates the intracellular from
extracellular fluid? - ✔✔Plasma Membrane
What is another name for the Plasma Membrane - ✔✔plasmalemma
What are three things the membrane is composed of and what is embedded in the
membrane? - ✔✔Double layer of lipids; phospholipids, cholesterol, glycolipids; proteins are
embedded
What is the most abundant lipid in the plasma membrane? - ✔✔phospholipids
The heads of phospoholipids are (Hydrophilic/hydrophobic) - ✔✔Hydrophilic
The tails of phospholipids are (Hydrophilic/hydrophobic) - ✔✔Hydrophobic
What are the two types of membrane proteins? - ✔✔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. - ✔✔Integral Proteins
What proteins are mostly on the cytoplasmic side and support that side by a network of
filaments? - ✔✔Peripheral Proteins
What is Active Transport? - ✔✔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? - ✔✔Large particles and macromolecules pass through
the membrane by this mechanism.
, What are the two types of Bulk Transport? - ✔✔Exocytosis and Endocytosis
What is Exocytosis? - ✔✔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? - ✔✔Mucus and Protein secretions from the glands in the
body
What is Endocytosis? - ✔✔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? - ✔✔Phagocytosis, Pinocytosis, and Recptor-
Mediated Endocytosis
What is Phagocytosis? (AKA Cell Eating) - ✔✔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? - ✔✔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) - ✔✔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? - ✔✔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.
