Dynamic Study Module CHAPTER 3: Cells and Tissues

A(n) __________ is the smallest living unit.

cell

Passage of materials across the plasma membrane from a region of high concentration to one of lower concentration is termed________

diffusion

The four primary tissue types

epithelium, connective tissue, nervous tissue, and muscle

the correct sequence of the events of protein synthesis

1) mRNA is made on the DNA template. 2) mRNA attaches to the ribosome to begin protein synthesis, and translation begins. 3) A tRNA with the anticodon that matches the mRNA codon recognizes the complementary mRNA codon calling for its amino acid and brings in the correct amino acid by binding via its anticodon to the codon. 4) As each tRNA brings in an amino acid, the ribosome moves along the mRNA, and a new amino acid is added to the growing peptide chain. 5) The previous tRNA is released back to the cytoplasmic pool.

Hypotonic solution

A solution that contains fewer dissolved particles (such as salt and other electrolytes) than is found in normal cells and blood

Microvilli and cell junctions are specializations of which major cell region?

Plasma Membrane

Type of epithelial tissue that functions in absorption and secretion; lines most of the respiratory tract.

Pseudostratified columnar epithelial tissue

Type of epithelial tissue that lines the entire length of the digestive tract from the stomach to the anus. It functions in secretion and absorption.

Simple columnar epithelial tissue

Type of epithelial tissue that is common in glands and their ducts.

Simple cuboidal epithelial tissue

Which type of epithelial tissue usually forms membranes where filtration, or exchange of substances by diffusion, occurs?

Simple squamous epithelial tissue Simple squamous epithelium is in the air sacs of the lungs, where oxygen and carbon dioxide are exchanged, and it forms the walls of capillaries, where nutrients and gases pass between the tissue cells and the blood in the capillaries.

________ represents active transport

Solute pumps Active transport uses ATP to energize its protein carriers, which are called solute pumps. The unassisted diffusion of solutes through the plasma membrane (or any selectively permeable membrane) is called simple diffusion. Molecules move down their concentration gradient, from a region where they are more concentrated to a region where they are less concentrated. Filtration is the process by which water and solutes are forced through a membrane (or capillary wall) by fluid, or hydrostatic, pressure. Facilitated diffusion follows the laws of diffusion to provide passage for substances that are both lipid-insoluble and too large to pass through the membrane pores.

Type of epithelial tissue that is found in sites that receive a good deal of abuse or friction, such as the esophagus, the mouth, and the outer portion of the skin.

Stratified squamous epithelial tissue

Most connective tissue types are well vascularized, meaning they have a rich blood supply. Which connective tissue represent(s) an EXCEPTION?

Tendons and ligaments Tendons and ligaments are NOT well vascularized. Consequently, they heal very slowly when injured. Most connective tissues are well vascularized.

hypertonic solution

a solution with a higher concentration of solutes and less water outside the cell than inside the cell. In these solutions, cells lose water by osmosis and crenate.

Centrioles

best known for their role in generating microtubules, and during cell division, the centrioles direct the formation of the mitotic spindle.

Of the different types of muscle tissue, only __________ is both involuntary AND contains intercalated discs.

cardiac muscle

Mitochondria

carry out the reactions in which oxygen is used to break down foods.

Which tissue type is usually composed of a large amount of extracellular matter.

connective tissue Connective tissues are made up of many different types of cells plus varying amounts of a nonliving substance found outside the cells, called the extracellular matrix. Connective tissues perform many functions, but they are primarily involved in protecting, supporting, and binding together other body tissues. Simple epithelia are arranged in a single layer of cells. Stratified epithelia consist of cells arranged in many strata (layers). Epithelial tissues have one surface exposed to the exterior of the body or to the interior of a hollow structure. Neural tissue runs through the brain and spinal cord.

Solution A has triple the salt content of normal blood plasma. The solution is __________, and in it red blood cells will __________.

hypertonic; shrink or crenate

Cells in a __________ solution will burst (lyse) as water rushes into the cell in an attempt to reach osmotic balance.

hypotonic

The __________ scattered in the lipid bilayer is/are responsible for most of the specialized functions of the plasma membrane.

proteins Some proteins are enzymes. Many of the proteins protruding from the cell exterior are receptors for hormones or other chemical messengers or are binding sites for anchoring the cell to fibers or to other structures inside or outside the cell. Most proteins that span the membrane are involved in transport. The structure of the plasma membrane consists of two lipid (fat) layers arranged "tail to tail." Most of the lipid portion is phospholipids, but a substantial amount of cholesterol is found in plasma membranes too. Nucleic acids include DNA and RNA, found in the nucleus and cytoplasm of a cell.

Endoplasmic reticulum

serves as a minicirculatory system for the cell because it provides a network of channels for carrying substances from one part of the cell to another.

The job of the Golgi apparatus is to package __________ for export from the cell.

proteins

The modification and packaging of proteins and their transport to the cell membrane for secretion is the role of the __________.

Golgi apparatus It is generally found close to the nucleus and is the principal "traffic director" for cellular proteins.

In an area where an epithelium is subjected to considerable wear and tear, you would expect to find __________.

stratified squamous epithelium tratified squamous epithelium is found in sites that receive a good deal of abuse or friction, such as the esophagus, the mouth, and the outer portion of the skin. Stratified epithelia consist of two or more cell layers. Being considerably more durable than the simple epithelia, these epithelia function primarily to protect. Simple squamous epithelium is a single layer of thin squamous cells resting on a basement membrane. Because simple epithelia are usually very thin, protection is not one of their specialties. Transitional epithelium is a highly modified, stratified squamous epithelium that forms the lining of parts of the urinary system that are subject to considerable stretching. Simple cuboidal epithelium, which is one layer of cuboidal cells. Because simple epithelia are usually very thin, protection is not one of their specialties. Simple columnar epithelium is made up of a single layer of tall cells that fit closely together. Because simple epithelia are usually very thin, protection is not one of their specialties.

Groups of cells that are similar in structure and function are called __________.

tissues

Lysosomes

membranous "bags" containing powerful digestive enzymes.

Which of the following cell organelles has/have double membranes and function(s) to supply most of the ATP used by the cell?

mitochondria

The tendency of water to move down its own concentration gradient is a characteristic of the process called __________.

osmosis

In __________, adjacent plasma membranes fuse together tightly, like a zipper.

tight junctions In tight junctions, adjacent plasma membranes fuse together tightly, like a zipper, and prevent substances from passing through the extracellular space between cells. Tight junctions are impermeable junctions that encircle the cells and bind them together into leakproof sheets. Desmosomes are anchoring junctions scattered like rivets along the sides of abutting cells. Gap junctions connect neighboring cells with hollow cylinders composed of proteins (called connexons) that span the entire width of the abutting membranes. Microvilli increase the cell's surface area for absorption.

The essential molecule __________ comprises over 60 percent of any living organism's cells.

water The four elements that make up most of a cell are carbon, oxygen, hydrogen, and nitrogen. These are combined into molecules, such as water and protein. The major building material of the cell is protein. Salts made of the element calcium are responsible for the hardness of bone.