BSC 3096 Chapter 3

Cell membranes are mainly constructed from __________. lipids and proteins carbohydrates and proteins lipids and carbohydrates nucleic acid and proteins

Lipids and proteins

Cell membranes are said to be freely permeable. selectively permeable. impermeable. actively permeable. None of the answers are correct.

Selectively permeable.

In which body cavity does the heart sit? Thoracic cavity Peritoneal cavity Cranial cavity Pleural cavity

Thoracic cavity

This junction contributes to the blood-brain barrier. desmosome tight junction gap junction anchoring junction neuromuscular junction

Tight junction

Mitochondrion

powerhouse of the cell where most ATP is produced

Define cytoskeleton. List five functions of the cytoskeleton.

A flexible, changeable, three-dimensional scaffold of actin, microfilaments, intermediate filaments, and microtubules. Functions: mechanical strength; stabilize position of organelles; transport material; link cells together; movement.

Cells that store fat are called liposomes. melanocytes. adipocytes. mast cells. fibroblasts

Adipocytes.

The nucleus stores all the information needed to synthesize which of the following molecules? proteins lipids phospholipids carbohydrates All of the answers are correct.

All of the answers are correct.

The disappearance of _________ junctions may occur when cancer cells metastasize. anchoring occluding tight communicating protective

Anchoring

List, compare, and contrast the three types of cell junctions and their subtypes. Give an example of where each type can be found in the body and describe its function in that location.

Anchoring junctions (skin)—allow twisting and stretching of tissue. Tight junctions (epithelia)—prevent movement of materials between cells. Gap junctions (some muscles)—allow material to pass directly from cytoplasm of one cell to another.

List the four general functions of the cell membrane.

Barrier between cell and ECF; regulate exchange of material between cell and ECF; transfer information between the cell and other cells; provide structural support.

Which is true for both muscle and neural tissues? ability to contract and generate force can generate and propagate electrical signals have extensive extracellular matrix lack gap junctions support is provided by glial cells

Can generate and propagate electrical signals

Which tissue would likely have cells with the greatest number of gap junctions? epidermis cardiac muscle the mucosal layer of the GI tract bone

Cardiac muscle

List the four major tissue types. Give an example and location of each.

Connective tissue (tendons that hold muscles to bones); epithelium (skin); neural tissue (the brain); and muscular tissue (heart and skeletal muscles)

Which tissue or cell type is not paired with the correct effect? epithelial: reabsorption in the kidney tubules smooth muscle: vasoconstriction of blood vessels connective: secretion of hormones into the blood cardiac muscle: increase force of heart contraction skeletal muscle: knee jerk reflex

Connective: secretion of hormones into the blood

The type of protein found in gap junctions is the occludin. cadherin. integrin. claudin. connexin

Connexin

Cystosol Membranous Organelles Inclusions Cytoskeleton

Cytoplasm

Microfilaments Intermediate filaments Microtubules

Cytoskeleton

If a cell lacked lysosomes, it would not be able to transport water-soluble molecules. digest cellular wastes and bacteria. synthesize lipids. produce enzymes. Destroy H2O2

Digeste cellular wastes and bacteria.

glands release hormones, which enter the blood and regulate the activities of organs or systems.

Endocrine

The cellular organelle(s) responsible for packaging and transporting proteins is/are the microtubules. rough endoplasmic reticulum. Golgi complex. ribosomes. mitochondria.

Golgi complex.

Which are involved in cell-matrix interactions? hemidesmosomes tight junctions focal adhesions desmosomes A and C

Hemidesmosomes and focal adhesions

Lipid droplets Glycogen Granules Ribosomes

Inclusions

Define and distinguish between inclusions and organelles. Give an example of each.

Inclusions: particles of insoluble material, such as glycogen and ribosomes. Organelles, such as mitochondria and Golgi apparatus, are separated from cytosol by membranes.

Define interstitial fluid, indicating whether it is inside or outside cells (intracellular or extracellular). A. Interstitial fluid is the intracellular fluid of the blood cells. B. Interstitial fluid is the extracellular fluid inside the circulatory system. C. Interstitial fluid is the intracellular fluid found in all cell types. D. Interstitial fluid is extracellular fluid outside the circulatory system and the cells.

Interstitial fluid is extracellular fluid outside the circulatory system and the cells.

Cell membranes are made up of mainly of which two molecules? proteins and carbohydrates lipids and carbohydrates lipids and nucleotides lipids and proteins

Lipids and proteins

All but one of the structures listed below are a type of cell junction. Identify the exception. gap junctions adherens junctions tight junctions desmosomes loose junctions

Loose junctions

What is the name of the hollow interior of an organ? A. Sphere B. Cavity C. Core D. Lumen

Lumen

The space that is surrounded by the tissue wall of hollow organs is known as the peritoneal cavity. extracellular space. lumen. epidural space. tract.

Lumen.

Cancer is abnormal, uncontrolled cell division. What property of epithelial tissues might (and does) make them more prone to developing cancer?

MMPs are enzymes that dissolve the extracellular matrix, so blocking them might inhibit tissue growth and repair

Mitochondria Endoplasmic Reticulum Golgi apparatus Lysosomes Peroxisomes

Membranous Organelles

The protein actin is associated with which of the following structures? intermediate filaments ribosomes microtubules microfilaments

Microfilaments

The tissue(s) that is/are considered excitable because of the ability to generate electrical signals is/are called ________ tissue. muscle epithelial neural muscle tissue and neural muscle tissue, neural tissue, and epithelial

Muscle tissue and neural

__________ is a tissue that is modified to transmit chemical and electrical signals from one cell to another.

Neural

Communication between the nucleus and cytosol occurs through nucleoli. sodium channels. nuclear pores. desmosomes. plasmalemma.

Nuclear pores.

Each is part of the cytoplasm except the nucleus. cytosol. organelles. cytoskeleton. inclusions.

Nucleus.

Each of the following is a primary tissue type except one. Identify the exception. neural tissue muscle tissue epithelial tissue osseous tissue connective tissue

Osseous tissue

What are the two primary types of biomolecules found in the cell membrane?

Phospholipids and proteins

Each of the following is true about cell membranes except the lipid:protein ratio varies widely depending on the metabolic activity of the cell. phospholipids are arranged with hydrophobic ends facing the extracellular space. phospholipids are arranged with hydrophilic ends facing the intracellular space. phospholipids, sphingolipids, and cholesterol are all found in cell membranes.

Phospholipids are arranged with hydrophobic ends facing the extracellular space.

In 1972, Singer and Nicolson proposed the fluid mosaic model of the cell membrane. According to this model, the membrane is composed of a bilayer of and a variety of embedded , with on the extracellular surface.

Phospholipids, proteins, carbohydrates

Which two fluid compartments make up the extracellular fluid? Intracellular fluid and plasma Interstitial fluid and intracellular fluid Cytosol and plasma Plasma and interstitial fluid

Plasma and interstitial fluid

Cells that form a tissue are held together by __________. proteins lipids carbohydrates nucleic acids

Proteins

Which of the following is NOT a molecule synthesized in the smooth endoplasmic reticulum (SER)? fatty acids lipids proteins steroids All are synthesized in the SER

Proteins

All of the following are synthesized along various sites of the endoplasmic reticulum except one. Identify the exception. steroids RNA proteins phospholipids fatty acids

RNA

The beta cells of the pancreas produce insulin, a protein-based hormone. Which of the following organelles would be found in higher levels in the beta cells? mitochondria ribosomes lysosomes microvilli

Ribosomes

Which would have more rough endoplasmic reticulum: pancreatic cells that manufacture the protein hormone insulin, or adrenal cortex cells that synthesize the steroid hormone cortisol?

Rough ER is where proteins are made, so pancreatic cells would have more.

Hepatocytes, the main functional cells of the liver, are very active in protein synthesis. Which organelle would you expect to be the increased in their cytoplasm? rough endoplasmic reticulum lysosome Golgi complex smooth endoplasmic reticulum centrosome

Rough endoplasmic reticulum

Which of the following consists of a network of intracellular membranes with attached ribosomes? smooth endoplasmic reticulum rough endoplasmic reticulum nucleoli mitochondria Golgi apparatus

Rough endoplasmic reticulum

Leydig cells are specialized testosterone-producing cells in the testes. Which organelle would you expect to be increased in their cytoplasm? Golgi complex smooth endoplasmic reticulum peroxisome rough endoplasmic reticulum mitochondrion

Smooth endoplasmic reticulum

Functions of epithelia include all of the following EXCEPT producing specialized secretions. storing energy reserves. controlling absorption. providing physical protection. controlling permeability.

Storing energy reserves.

Centrosome

The microtubule-organizing center

Each of the following statements concerning mitochondria is TRUE except one. Identify the exception. A. The mitochondrial cristae increase the inner surface area of the organelle. B. The mitochondria produce most of a cell's ATP. C. The mitochondria contain no DNA or RNA. D. Respiratory enzymes are attached to the surface of the cristae. E. The matrix of the mitochondria contains metabolic enzymes involved in energy production.

The mitochondria contain no DNA or RNA.

The term secretion refers to A. the manufacture and assembly of a material. B. synthesis of a protein for export from the cell. C. the process by which a cell releases a substance into the extracellular space. D. storage of a material, until it is time for it to leave the cell. E. None of the answers describe secretion.

The process by which a cell releases a substance into the extracellular space.

________ proteins extend all the way across the cell membrane. Transmembrane Peripheral Nuclear Glycolipid Cytoskeletal

Transmembrane

A number of organelles can be considered vesicles. Define vesicle and describe at least three examples.

Vesicles—membranous spheres. Examples: lysosomes, peroxisomes, secretory vesicles.

Centriole

a bundle of microtubules that aid in mitosis

Which cell junctions are paired with a correct example and description? tight junctions (cardiomyocytes); prevent movement of materials between cells anchoring junctions (cardiomyocytes); contribute to the mechanical strength of the tissue gap junctions (epidermis); allow direct and rapid cell-to-cell communication More than one of the above

anchoring junctions (cardiomyocytes); contribute to the mechanical strength of the tissue

cytoplasm vs cytosol

cytoplasm—everything inside the cell except the nucleus; cytosol—semi-gelatinous, intracellular fluid.

Peroxisomes

degrades long-chain fatty acids and toxic foreign molecules

Lysosome

digestive system of cell, degrading or recycling components

Flagelolum

in human cells, appears as single, long, whiplike tail

Arrange the following compartments in the order a glucose molecule entering the body at the intestine would encounter them: interstitial fluid, plasma, intracellular fluid. Which of these fluid compartments is/are considered extracellular fluid(s)?

intracellular fluid; interstitial fluid; plasma. Interstitial fluid and plasma are ECF.

Lumen vs. wall

lumen—hollow inside of an organ or tube; wall—cell layer.

The term matrix can be used in reference to an organelle or to tissues. Compare the meanings of the term in these two contexts.

mitochondrial matrix—the internal compartment; tissue matrix—noncellular material found outside cells

Golgi apparatus

modifies and packages proteins into vesicles

Myosin vs. keratin

myosin—motor protein filament; keratin—structural protein fiber.

Endoplasmic Reticulum

network of membranous tubules that synthesize biomolecules

Cilia

short, hairlike structures that beat to produce currents in fluids