Human Anatomy & Physiology Exam Review #2
Cellular Organelles & their functions
• Chromosomes: (Genes & DNA) organized structure of DNA and protein that is found in
nucleus of the cell. It is a single piece of coiled DNA containing many genes, regulatory
elements and other nucleotide sequences. Chromosomes also contain DNA-bound proteins,
which serve to package the DNA and control its functions.
• Endoplasmic Reticulum: (Called the "intracellular highway" because it is for transporting
all sorts of items around the cell.) Rough ER is studded with ribosomes; tubules of the rough
ER provide an area for storage and transport of the proteins made on the ribosomes to other
cell areas. Smooth ER, which has no function in protein synthesis, is a site of steroid and
lipid synthesis, lipid metabolism, and drug detoxification.
• Golgi Apparatus: (Make, process and package proteins.) Stack (like pancakes) of flattened
sacs with bulbous and associated small vesicles; found close to the nucleus. A major function
is the modifying, sorting and packaging of proteins for secretion. A substance passes through
the Golgi and comes out with a coating so that it’s safe.
• Lysosomes: (Contains hydrolytic enzymes that only take things apart and targeting digestive
processes/protective function …immune system) Lysosomes are organelles that contain
digestive enzymes. They digest excess or worn out organelles, food particles, and engulfed
viruses or bacteria.
• Mitochondria: (Provides the energy for all the activated that take place in the cell.)
Generally rod-shaped bodies with a double-membrane wall; contain enzymes that oxidize
foodstuffs to produce cellular energy (ATP); often referred to as "powerhouses of the cell.”
Make energy out of food.
• Nucleus: The “brains” of the cell, the nucleus directs cell activities and contains genetic
material called chromosomes made of DNA. (operating system of the cell)
• Plasma (Cell) Membrane: keep toxic substances out of the cell; contain receptors and
channels that allow specific molecules in and out of the cytoplasm, such as ions, nutrients,
, wastes, and metabolic products, that mediate cellular and extracellular activities to pass
between organelles and between the cell and the outside environment
• Ribosomes: (build up of proteins) Tiny spherical bodies composed of RNA and protein;
floating free or attached to a membranous structure of (the rough ER)in the cytoplasm.
Actual sites of protein synthesis.
• Cytoplasm: The jelly-like fluid that fills a cell is called cytoplasm. It is made up of mostly
water and salt. Cytoplasm is present within the cell membrane of all cell types and contains
all organelles and cell parts.
Movement of Materials Across Plasma (Cell) Membrane:
• How does the structure of the cell membrane permit different substances to move into and
out of the cell?
• Cell membrane functions as a semi-permeable barrier; allow some materials to pass
while constraining the movement of other molecules
• What is meant by selective permeability? (Google: selectively permeable membrane.)
• Ability of the cell membrane to allow certain substances/molecules/ions to pass
through while keeping others out (enter/exit the cell) by means of active or passive
transport
• What role does a concentration gradient play in this:
• Hypotonic: Contains a lower concentration of dissolved substance on the outside;
inside has a higher concentration; water goes into the cell/dialysis tubing (stimulates
cell membrane) and it swells
• Hypertonic: Contains a higher concentration of dissolved substance on the outside;
inside has a lower concentration; water moves out of the cell/dialysis tubing and it
shrinks
• Isotonic: Same concentration on outside and inside; water goes in and out both
directions in exchange
• Passive Transport: No energy necessary
• Diffusion: [High] —> [Low]
• Molecule move from high concentration to low concentration
Cellular Organelles & their functions
• Chromosomes: (Genes & DNA) organized structure of DNA and protein that is found in
nucleus of the cell. It is a single piece of coiled DNA containing many genes, regulatory
elements and other nucleotide sequences. Chromosomes also contain DNA-bound proteins,
which serve to package the DNA and control its functions.
• Endoplasmic Reticulum: (Called the "intracellular highway" because it is for transporting
all sorts of items around the cell.) Rough ER is studded with ribosomes; tubules of the rough
ER provide an area for storage and transport of the proteins made on the ribosomes to other
cell areas. Smooth ER, which has no function in protein synthesis, is a site of steroid and
lipid synthesis, lipid metabolism, and drug detoxification.
• Golgi Apparatus: (Make, process and package proteins.) Stack (like pancakes) of flattened
sacs with bulbous and associated small vesicles; found close to the nucleus. A major function
is the modifying, sorting and packaging of proteins for secretion. A substance passes through
the Golgi and comes out with a coating so that it’s safe.
• Lysosomes: (Contains hydrolytic enzymes that only take things apart and targeting digestive
processes/protective function …immune system) Lysosomes are organelles that contain
digestive enzymes. They digest excess or worn out organelles, food particles, and engulfed
viruses or bacteria.
• Mitochondria: (Provides the energy for all the activated that take place in the cell.)
Generally rod-shaped bodies with a double-membrane wall; contain enzymes that oxidize
foodstuffs to produce cellular energy (ATP); often referred to as "powerhouses of the cell.”
Make energy out of food.
• Nucleus: The “brains” of the cell, the nucleus directs cell activities and contains genetic
material called chromosomes made of DNA. (operating system of the cell)
• Plasma (Cell) Membrane: keep toxic substances out of the cell; contain receptors and
channels that allow specific molecules in and out of the cytoplasm, such as ions, nutrients,
, wastes, and metabolic products, that mediate cellular and extracellular activities to pass
between organelles and between the cell and the outside environment
• Ribosomes: (build up of proteins) Tiny spherical bodies composed of RNA and protein;
floating free or attached to a membranous structure of (the rough ER)in the cytoplasm.
Actual sites of protein synthesis.
• Cytoplasm: The jelly-like fluid that fills a cell is called cytoplasm. It is made up of mostly
water and salt. Cytoplasm is present within the cell membrane of all cell types and contains
all organelles and cell parts.
Movement of Materials Across Plasma (Cell) Membrane:
• How does the structure of the cell membrane permit different substances to move into and
out of the cell?
• Cell membrane functions as a semi-permeable barrier; allow some materials to pass
while constraining the movement of other molecules
• What is meant by selective permeability? (Google: selectively permeable membrane.)
• Ability of the cell membrane to allow certain substances/molecules/ions to pass
through while keeping others out (enter/exit the cell) by means of active or passive
transport
• What role does a concentration gradient play in this:
• Hypotonic: Contains a lower concentration of dissolved substance on the outside;
inside has a higher concentration; water goes into the cell/dialysis tubing (stimulates
cell membrane) and it swells
• Hypertonic: Contains a higher concentration of dissolved substance on the outside;
inside has a lower concentration; water moves out of the cell/dialysis tubing and it
shrinks
• Isotonic: Same concentration on outside and inside; water goes in and out both
directions in exchange
• Passive Transport: No energy necessary
• Diffusion: [High] —> [Low]
• Molecule move from high concentration to low concentration
