CELL

Question 1

are the basic structural and functional units, the smallest living parts of the body.

Answer 1

cells

Question 2

fluid containing a system of membranous organelles, non-membranous molecular assemblies, and a cytoskeleton.

Answer 2

cytoplasm

Question 3

The first zygotic cellular divisions produce cells called

Answer 3

blastomeres

Question 4

Explanted to tissue culture cells of the inner cell mass are called

Answer 4

embryonic stem cells

Question 5

Most cells of the fetus undergo a specialization process called ___ in which they predominantly express sets of genes that mediate specific cytoplasmic activities, becoming efficiently organized in tissues with specialized functions and usually changing their shape accordingly

Answer 5

differentiation

Question 6

Movement

Answer 6

Muscles and other contractile cells

Question 7

Form adhesive and tight junctions between cells

Answer 7

Epithelial cells

Question 8

Synthesize and secrete components of the extracellular matrix

Answer 8

Fibroblasts, cells of bone and cartilage

Question 9

Convert physical and chemical stimuli into action potentials

Answer 9

Neurons and sensory cells

Question 10

Synthesis and secretion of degradative enzymes

Answer 10

Cells of digestive glands

Question 11

Synthesis and secretion of glycoproteins

Answer 11

Cells of mucous glands

Question 12

Synthesis and secretion of steroids

Answer 12

Certain cells of the adrenal gland, testis, and ovary

Question 13

Ion transport

Answer 13

Cells of the kidney and salivary gland ducts

Question 14

Intracellular digestion

Answer 14

Macrophages and neutrophils

Question 15

Lipid storage

Answer 15

Fat cells

Question 16

metabolite absorption

Answer 16

Cells lining in the intestine

Question 17

consists of phospholipids, cholesterol and proteins, with oligosaccharide chains covalently linked to many of the phospholipids and proteins.

This limiting membrane functions as a selective barrier regulating the passage of materials into and out of the cell and facilitating the transport of specific molecules.

Answer 17

Plasma membrane

Question 18

Certain plasma membrane proteins, the ___ , are linked to both the cytoskeleton and ECM components and allow continuous exchange of influences, in both directions, between the cytoplasm and material in the ECM.

Answer 18

integrins

Question 19

__ are major constituents of membranes

Answer 19

Proteins

Question 20

__ are incorporated directly within the lipid bilayer. whereas peripheral proteins are bound to one of the two membrane surfaces, particularly on the cytoplasmic side.

Answer 20

Integral proteins

Question 21

___ transports small, nonpolar molecules directly through the lipid bilayer. Lipophilic (fat-soluble) molecules diffuse through membranes readily. water very slowly.

Answer 21

Diffusion

Question 22

__ are multipass proteins forming transmembrane pores through which ions or small molecules pass selectively.

Answer 22

Channels

Question 23

Water molecules usually cross the plasma membrane through channel proteins called __ .

Answer 23

aquaporins

Question 24

__ are transmembrane proteins that bind small molecules and translocate them across the membrane via conformational changes.

Answer 24

Carriers

Question 25

are enzymes engaged in active transport, utilizing energy from the hydrolysis of adenosine triphosphate (ATP) to move ions and other solutes across membranes, against often steep concentration gradients.

Answer 25

Membrane pumps

Question 26

Macromolecules normally enter cells by being enclosed within folds of plasma membrane (often after binding specific membrane receptors) which fuse and pinch off internally as spherical cytoplasmic vesicles (or vacuoles) in a general process known as

Answer 26

endocytosis

Question 27

("cell drinking") involves smaller invaginations of the cell membrane which fuse and entrap extracellular fluid and its dissolved contents.

Answer 27

Pinocytosis

Question 28

The latter process, called __ , accomplishes bulk transfer of dissolved substances across the cell.

Answer 28

transcytosis

Question 29

Receptors for many substances, such as low-density lipoproteins and protein hormones, are integral membrane proteins at the cell surface High-affinity binding of such ligands to their receptors causes these proteins to aggregate in special membrane regions that then invaginate and pinch off internally as vesicles.

Answer 29

Receptor-mediated endocytosis

Question 30

are macromolecular machines, about 20 x 30 nm in size. which assemble polypeptides from amino acids

Answer 30

Ribosomes

Question 31

The cytoplasm of most cells contains a convoluted membranous network called the __

Answer 31

endoplasmic reticulum (ER).

Question 32

This network (reticulum) extends from the surface of the nucleus throughout most of the cytoplasm and encloses a series of intercommunicating channels called __ .

Answer 32

cisternae

Question 33

is a major site for vital cellular activities, including biosynthesis of proteins and lipids.

Answer 33

ER

Question 34

is prominent in cells specialized for protein secretion, such as pancreatic acinar cells (making digestive enzymes), fibroblasts (collagen), and plasma cells (immunoglobulins). The presence of polyribosomes on the cytosolic surface of the RER confers basophilic staining properties on this organelle when viewed with the light microscope. The major function is production of membrane-associated proteins, proteins of many membranous organelles, and proteins to be secreted by exocytosis.

Answer 34

Rough Endoplasmic Reticulum

Question 35

Regions of ER that lack bound polyribosomes, which is continuous with RER but frequently less abundant. Lacking polyribosomes, __ is not basophilic and is best seen with the TEM.

Answer 35

Smooth Endoplasmic Reticulum

Question 36

completes posttranslational modifications of proteins produced in the RER and then packages and addresses these proteins to their proper destinations.

Answer 36

Golgi Apparatus

Question 37

Golgi Apparatus, The organelle was named after histologist___ who discovered it in 1898

Answer 37

Camillo Golgi

Question 38

sites of intracellular digestion and turnover of cellular components are membrane-limited vesicles that contain about 40 different hydrolytic enzymes and are particularly abundant in cells with great phagocytic activity (eg, macrophages neutrophils).

Answer 38

Lysosomes (Gr. lysis, solution + soma, body)

Question 39

are membrane- enclosed organelles with arrays of enzymes specialized for aerobic respiration and production of adenosine triphosphate (ATP), with high- energy phosphate bonds, which supplies energy for most cellular activines

Answer 39

Mitochondria

Question 40

converts glucose anaerobically to pyruvate in the cytoplasm releasing some energy.

Answer 40

Glycolysis

Question 41

The cytoskeleton contains three types of polymers

Answer 41

Microtubules Microfilaments Myosins

Question 42

are semirigid tubular structures with walls composed of polymerized tubulin heterodimers; their structure is often very dynamic, with steady addition and dissociation of tubulin

Answer 42

Microtubules

Question 43

are short, flexible, highly dynamic filaments of actin subunits. in which changes in length and interactions with binding proteins regulate cytoplasmic viscosity and movement.

Answer 43

Microfilaments

Question 44

are motor proteins that bind and move along actin filaments. carrying vesicles or producing cytoplasmic movement.

Answer 44

Myosins