CUNY York- Bio 140: Human Biology
Structure and function of cells and membranes, and tissues as well as muscle and the nervous
system.
Know the differences between eukaryotic and prokaryotic cells.
● The defining characteristic feature that distinguishes between prokaryotic and eukaryotic
cells is the nucleus.
● Prokaryotic cells have no organelles enclosed in plasma membranes
● Every eukaryotic cell has a nucleus and organelles, each enclosed in plasma
membranes.
Know the major organelles found in eukaryotic cells and what the organelles do.
Describe the structure and function of the plasma membrane. What is the difference between
osmosis, passive diffusion, facilitated diffusion and active transport?
● The primary function of the plasma membrane is to protect the cell from its
surroundings. Composed of a phospholipid bilayer with embedded proteins, the
plasma membrane is selectively permeable to ions and organic molecules and
regulates the movement of substances in and out of cells.
● Osmosis is the diffusion of water through a semipermeable membrane according to the
concentration gradient of water across the membrane, water always moves from an area
of higher concentration (of water) to one of lower concentration (of water).
● Passive Diffusion does not require energy to transport. A single substance tends to
move from an area of high concentration to an area of low concentration until the
concentration is equal across the space.
● In facilitated diffusion, material moves across the plasma membrane with the assistance
of transmembrane proteins down a concentration gradient (from high to low
concentration) without the expenditure of cellular energy.
● Active transport is the energy-requiring (ATP) process of pumping molecules and ions
across membranes "uphill" - against a concentration gradient.
, Describe the movement of water when cells are placed in hyper-, hypo- or isosmotic solutions.
● If a cell is placed in a hypertonic solution, there will be a net flow of water out of the
cell, and the cell will lose volume.
● If a cell is placed in a hypotonic solution, there will be a net flow of water into the cell,
and the cell will gain volume.
● If a cell is placed in an isotonic solution, there will be no net flow of water into or out of
the cell, and the cell’s volume will remain stable.
What is the difference between endocytosis and exocytosis?
● Endocytosis is a type of active transport that moves particles, such as large molecules,
parts of cells, and even whole cells, into a cell. Examples include phagocytosis,
pinocytosis, receptor-mediated endocytosis. Exocytosis is the opposite of the processes
discussed above in that its purpose is to expel material from the cell into the
extracellular fluid.
Name the primary tissue types and explain their roles in the body?
● Nervous tissue is composed of neurons—specialized cells that send, transport, and
receive information through electrochemical signaling—and supporting cells called glial
cells. A bundle of neurons is a nerve. A brain is the concentration of nervous tissue.
Besides controlling movement through the muscles, nervous tissue detects sensory
stimuli and is responsible for directing many of the activities of the body.
● Muscle cells can contract and expand, allowing the body and internal organs to move.
The cardiac muscle of the heart; the skeletal muscles that attach to bones and
smooth muscle found in visceral organs such as the intestines.
● Epithelial tissue consists of thin sheets of cells and includes the skin and the linings of
internal organs and body cavities. Epithelial cells are tightly packed, providing a barrier
Structure and function of cells and membranes, and tissues as well as muscle and the nervous
system.
Know the differences between eukaryotic and prokaryotic cells.
● The defining characteristic feature that distinguishes between prokaryotic and eukaryotic
cells is the nucleus.
● Prokaryotic cells have no organelles enclosed in plasma membranes
● Every eukaryotic cell has a nucleus and organelles, each enclosed in plasma
membranes.
Know the major organelles found in eukaryotic cells and what the organelles do.
Describe the structure and function of the plasma membrane. What is the difference between
osmosis, passive diffusion, facilitated diffusion and active transport?
● The primary function of the plasma membrane is to protect the cell from its
surroundings. Composed of a phospholipid bilayer with embedded proteins, the
plasma membrane is selectively permeable to ions and organic molecules and
regulates the movement of substances in and out of cells.
● Osmosis is the diffusion of water through a semipermeable membrane according to the
concentration gradient of water across the membrane, water always moves from an area
of higher concentration (of water) to one of lower concentration (of water).
● Passive Diffusion does not require energy to transport. A single substance tends to
move from an area of high concentration to an area of low concentration until the
concentration is equal across the space.
● In facilitated diffusion, material moves across the plasma membrane with the assistance
of transmembrane proteins down a concentration gradient (from high to low
concentration) without the expenditure of cellular energy.
● Active transport is the energy-requiring (ATP) process of pumping molecules and ions
across membranes "uphill" - against a concentration gradient.
, Describe the movement of water when cells are placed in hyper-, hypo- or isosmotic solutions.
● If a cell is placed in a hypertonic solution, there will be a net flow of water out of the
cell, and the cell will lose volume.
● If a cell is placed in a hypotonic solution, there will be a net flow of water into the cell,
and the cell will gain volume.
● If a cell is placed in an isotonic solution, there will be no net flow of water into or out of
the cell, and the cell’s volume will remain stable.
What is the difference between endocytosis and exocytosis?
● Endocytosis is a type of active transport that moves particles, such as large molecules,
parts of cells, and even whole cells, into a cell. Examples include phagocytosis,
pinocytosis, receptor-mediated endocytosis. Exocytosis is the opposite of the processes
discussed above in that its purpose is to expel material from the cell into the
extracellular fluid.
Name the primary tissue types and explain their roles in the body?
● Nervous tissue is composed of neurons—specialized cells that send, transport, and
receive information through electrochemical signaling—and supporting cells called glial
cells. A bundle of neurons is a nerve. A brain is the concentration of nervous tissue.
Besides controlling movement through the muscles, nervous tissue detects sensory
stimuli and is responsible for directing many of the activities of the body.
● Muscle cells can contract and expand, allowing the body and internal organs to move.
The cardiac muscle of the heart; the skeletal muscles that attach to bones and
smooth muscle found in visceral organs such as the intestines.
● Epithelial tissue consists of thin sheets of cells and includes the skin and the linings of
internal organs and body cavities. Epithelial cells are tightly packed, providing a barrier
