Week 2 Learning Outcomes

Question 1

Describe the structure of the plasma membrane and explain how the structure facilitates its functions

Answer 1

The plasma membrane separates the interior of the cell from the outside environment and is selectively-permeable

Question 2

Describe the structure and function of tight junctions

Answer 2

In Tight junctions adjacent plasma membranes fuse together tightly, like a zipper, and prevent substances from passing through the extracellular space between cells.

Question 3

Describe the structure and function of desmosomes

Answer 3

Desmosomes anchor neighbouring cells together but do not prevent leakage between cells.

Question 4

Describe the structure and function of gap junctions

Answer 4

Gap junctions are composed of transmembrane proteins called connexons that provide a direct passageway between neighbouring cells.

Question 5

Describe the structure and function of the nucleus

Answer 5

Organelle within the cell that contains chromosomes, stores the cells dna, and facilitates its transcription and replication.

Question 6

Describe the structure and function of the cytoplasm

Answer 6

Gel-like fluid inside the cell, integral part of both prokaryotic and eukaryotic cells, functions to house and maintain optimal environment for the cellular organelles

Question 7

Describe the structure and functions of smooth endoplasmic reticulum

Answer 7

Has a tubular form, and does not have ribosomes.
Helps in the production of phospholipids, the chief lipids in cell membranes and are essential in the process of metabolism. Smooth ER transports the products of the rough ER to other cellular organelles, especially the Golgi apparatus.

Question 8

Describe the structure and functions of rough endoplasmic reticulum

Answer 8

Made up of connected flattened sacs having several ribosomes on its outer surface.
It synthesizes and secretes proteins in the liver, hormones and other substances in the glands.
Rough ER is prominent in cells where protein synthesis happens.

Question 9

Describe the structure and functions of the Golgi apparatus

Answer 9

Helps process and package proteins and lipid molecules, especially proteins destined to be exported from the cell. Made up of a series of flattened stacked pouches called cisternae, located in the cytoplasm next to the endoplasmic reticulum and near the cell nucleus

Question 10

Describe the structure and functions of Lysosomes

Answer 10

Membrane enclosed organelle’s that contain enzymes capable of breaking down all kinds of biological polymers (proteins, nucleic acids, carbohydrates, lipids) They break down worn out cell parts

Question 11

Describe the structure and functions of Ribosomes

Answer 11

Responsible for making proteins, ribosomes in each cell are made up of two subunits, subunits lock around the messenger RNA and then travel along the length of the messenger RNA molecule reading each three-letter codon

Question 12

Describe the structure and functions of Cellular Extensions

Answer 12

Certain cells may have extensions that help the cell carry out its function. Certain cells may have long extensions such as flagella, cilia and villi.

Question 13

Explain the difference between passive and active transport across the plasma membrane

Answer 13

Passive transport does not require energy for the movement of molecules. Active transport requires energy for the movement of molecules (ATP)

Question 14

Define and describe simple diffusion and how it contributes to movement of specific substances across the plasma membrane

Answer 14

Simple Diffusion is when solutes constantly move from a high concentration to low concentration, without the use of ATP (E.g., liquid soluble solutes directly through the phospholipid bilayer)

Question 15

Define and describe facilitated diffusion and how it contributes to movement of specific substances across the plasma membrane.

Answer 15

Facilitated diffusion is when solutes move from high to low concentration via a carrier, a passive process.

Question 16

Define and describe the process of
osmosis and how it contributes to movement of water across the plasma membrane

Answer 16

The movement of water from a high concentration to low concentration across the a semipermeable membrane, based on solute difference.

Question 17

Define Hypotonic

Answer 17

Hypotonic: When a cell is placed in a hypotonic environment, water will enter the cell, and the cell will swell.

Question 18

Define Hypertonic

Answer 18

Hypertonic: If a cell is placed in a hypertonic solution, water will leave the cell, and the cell will shrink.

Question 19

Define Isotonic

Answer 19

Isotonic: In an isotonic environment, there is no net water movement, so there is no change in the size of the cell

Question 20

Define osmotic pressure and explain how it relates to fluid movement across the plasma
membrane.

Answer 20

Osmotic pressure is defined as the pressure that must be applied to the solution side to stop fluid movement when a semipermeable membrane separates a solution from pure water.

Question 21

Define and describe the processes of endocytosis and how it contributes to movement of substances across the plasma membrane

Answer 21

Endocytosis is the process of moving substances from outside the cell and engulfing them in a vesicle.
Vesicle forms and fuses with lysosome for digestion, transport to plasma membrane and exocytosis of vesicle contents, membranes and receptors (if present) recycled to plasma membrane

Question 22

Define and describe the processes of exocytosis and how it contributes to movement of substances across the plasma membrane

Answer 22

Exocytosis is the process of moving substances from within a cell to the exterior of a cell, requires energy making it a type a passive transport
The membrane bound vesicle migrates to the plasma membrane, there, docking proteins on the vesicle and plasma membrane bing, the vesicle and membrane fuse and a pore opens up, vesicle contents are released to the cell exterior.

Question 23

Describe the impact of aging on the cell.

Question 24

Review the definition of a tissue

Answer 24

A tissue is a group of cells that have similar structure and function as a unit

Question 25

The Four Major Tissue Types: Nervous Tissue

Answer 25

Internal communication and control
Hallmarks; irritable, conductive
Brain, spinal cord, and nerves

Question 26

The Four Major Tissue Types: Muscle Tissue

Answer 26

Contracts to cause movement
Hallmarks; irritable, contractile
Muscles attached to bones (skeletal)
Muscles of heart wall (cardiac)
Muscles of walls of hollow organs (smooth)

Question 27

The Four Major Tissue Types: Epithelial Tissue

Answer 27

Forms boundaries between different environments, protects, secretes, absorbs, filters
Hallmarks; One free (apical) surface, avascular
Linking of GI tract and other hollow organs
Skin surface (epidermis)

Question 28

The Four Major Tissue Types: Connective Tissue

Answer 28

Supports, protects, binds other tissues together
Hallmarks; extracellular matrix, varying vascularity
Cartilage
Bones
Tendons
Fat & other soft padding tissue

Question 29

Describe the difference between
endocrine and exocrine glands

Answer 29

Endocrine glands secrete products directly into the bloodstream and exocrine glands secrete substances into a ductal system to an epithelial surface.

Question 30

Epithelium Types: Simple Squamous

Answer 30

Lines blood vessels and body cavities and regulates the passage of substances into the underlying tissue

Question 31

Epithelium Types: Stratified Squamous

Answer 31

A single basal layer containing stem cells, 2–3 layers of proliferative basaloid cells in the suprabasal region, and larger keratinized cells toward the surface. Usually has protective functions, including protection against microorganisms from invading underlying tissue and/or protection against water loss.

Question 32

Epithelium Types: Simple cuboidal

Answer 32

A type of epithelium that consists of a single layer of cuboidal (cube-like) cells which have large, spherical and central nuclei. Offers secretory, absorptive, or excretory functions

Question 33

Epithelium Types: Simple columnar

Answer 33

A single layer of columnar epithelial cells which are tall and slender with oval-shaped nuclei located in the basal region, attached to the basement membrane. Lines most organs of the digestive tract including the stomach, and intestines.

Question 34

Epithelium Types: Pseudostratified ciliated columnar epithelium

Answer 34

Appears to have multiple layers, is only comprised of a single sheet of cells absorption and secretion of mucus, protection from foreign particles (dust, pathogens, and allergens), and transport of materials such as hormones and enzymes

Question 35

Epithelium Types: Transitional Epithelium

Answer 35

Made up of several layers of cells that become flattened when stretched lines most of your urinary tract and allows your bladder to expand

Question 36

Connective Tissue Types: Compact bone

Answer 36

Consists of units called osteons or Haversian systems. Osteons are cylindrical structures that contain a mineral matrix and living osteocytes connected by canaliculi, which transport blood provides protection and strength to bones

Question 37

Connective Tissue Types: Hyaline Cartilage

Answer 37

Slippery and smooth
helps your bones move smoothly past each other in your joints.
flexible but strong enough to help your joints hold their shape
Located At the ends of bones that form joints

Question 38

Connective Tissue Types: Elastic Cartilage

Answer 38

most flexible cartilage
supports parts of your body that need to bend and move to function
Can bounce back to its original shape, even after a strong force
E.g., ear is made of elastic cartilage

Question 39

Connective Tissue Types: Fibrocartilage

Answer 39

provides structural support for the musculoskeletal system
Very strong
found predominantly in the intervertebral disks of the spine and at the insertions of ligaments and tendons

Question 40

Connective Tissue Types: Dense Regular

Answer 40

Large, dense, and robust collagen fibers that are arranged in a parallel fashion.
Function is to bind organs together
Found in tendons, ligaments, aponeuroses

Question 41

Connective Tissue Types: Dense irregular

Answer 41

Has high portions of collagenous fibers
provides strength, making the skin resistant to tearing by stretching forces from different directions
makes up submucosa of the digestive tract, lymph nodes, and some types of fascia

Question 42

Connective Tissue Types: Areolar connective Tissue (LOOSE)

Answer 42

Widely distributed in the body
Primarily function as a packing material between other tissues
Provides support and helps to protect organs, muscles, and many other tissues
Helps to bind the skin together
Provides a protective framework that keeps major structures in place and offers support
Contains mast cells that help prevent infection.

Question 43

Connective Tissue Types: Adipose (LOOSE)

Answer 43

Serves as an energy storing reservoir, but it also insulates the body from extreme temperatures, cushions vital organs, and secretes hormones and biological factor

Question 44

Connective Tissue Types: Reticular

Answer 44

Provides structural support by creating and maintaining the fine networks of fibres that serve as the framework for most lymphoid organs
Found in lymphoid organs such as the spleen, red bone marrow, and lymph node stromal cells, their role is to create a stroma and offer structural support

Question 45

Connective Tissue Types: Blood

Answer 45

Connects all systems of the body and transports oxygen, nutrients, and wastes.

Question 46

Describe the structure, function and location of each type of muscle tissue.

Answer 46

Skeletal Muscle
Cardiac Muscle
Smooth Muscle

Question 47

Identify and describe the two types of cells in nervous tissue

Answer 47

Neurons and Neuroglia

Question 48

Describe the impact of aging on tissues and membranes.

Answer 48

Cell membranes change, so many tissues have more trouble getting oxygen and nutrients and removing carbon dioxide and other wastes. Many tissues lose mass. This process is called atrophy. Some tissues become lumpy (nodular) or more rigid.