A Tour of the Cell

Question 1

Basic Features of All Cells

Answer 1

plasma membrane, cytosol, chromosomes, ribosomes

Question 2

Location of DNA in Eukaryotes

Answer 2

Nucleus

Question 3

Location of DNA in Prokaryotes

Answer 3

Nucleoid (not membrane enclosed)

Question 4

Cytoplasm

Answer 4

Region between the nucleus and the plasma membrane

Question 5

Cytosol

Answer 5

semi-fluid substance in which organelles are suspended

Question 6

Flagellum

Answer 6

present in some animal cells, composed of microtubules in an extension of the plasma membrane

Question 7

Endoplasmic Reticulum

Answer 7

network of membranous sacs and tubes called cistern, membrane separates the internal cavity of ER called the ER lumen: active in membrane synthesis and other synthetic and metabolic processes; has rough and smooth regions

Question 8

Nuclear envelope

Answer 8

double membrane enclosing the nucleus: selectively permeable; perforated by pores, lined by pore complex which regulates entry and exit of protein, RNA, and large macromolecules; continuous with ER

Question 9

Nucleolus

Answer 9

structure inside nucleus involved in production of ribosomes; ribosomal RNA is synthesized and leaves nucleus through pore complex

Question 10

Chromatin

Answer 10

material consisting of DNA and proteins; in between Nuclear Envelope and Nucleolus

Question 11

Ribosomes

Answer 11

complexes that make proteins; either in cytosol (free ribosomes) or bound to rough ER or nuclear envelope (bound ribosomes)

Question 12

Lysosome

Answer 12

digestive organelle where macromolecules are hydrolyzed

Question 13

Mithocondrion

Answer 13

organelle where cellular respiration occurs and most ATP is generated, 2 layer membrane, inner layer (cristae), space between inner layer and outer layer (intermembraane space), second compartment (mitchondrial matrix)

Question 14

Peroxisome

Answer 14

organelle with various specialized metabolic functions; produces hydrogen peroxide as a by-product and converts it to water

Question 15

Microvilli

Answer 15

projections that increase surface area of cell

Question 16

Cytoskeleton

Answer 16

reinforces cell’s shape; functions in cell movement, components are made of protein (microfilaments, intermediate filaments, microtubules)

Question 17

Centrosome

Answer 17

region where the cell’s microtubules are initiated, include a pair of centrioles

Question 18

Plant Organelles

Answer 18

Central Vacuole, Chloroplast, Plasmodesmata, Cell Wall

Question 19

Cell Wall

Answer 19

Outer Layer that maintains cell shape: made of cellulose, protein, and polysaccharides

Question 20

Plasmodesmata

Answer 20

channel through cell wall that connect cytoplasm of neighboring cells

Question 21

Chloroplast

Answer 21

photosynthetic organelle; converts energy of sunlight to chemical energy

Question 22

Central Vacuole

Answer 22

organelle in older plant cells; function include storage, breakdown of macromolecules and waste products

Question 23

Nuclear Lamina

Answer 23

net of intermediate filaments that maintains shape of nucleus through nuclear envelope

Question 24

Endomembrane system

Answer 24

nuclear envelope, ER, Golgi apparatus, lysosomes, vesicles, vacuoles, plasma membrane

Question 25

Vesicles

Answer 25

sacs made of membrane used for transporting important biological molecules

Question 26

Smooth ER

Answer 26

outer surface lacks ribosomes, enzymes in smooth ER help with synthesis of lipids, detoxify drugs and poisons (prevalent in liver cells), stores calcium ions in ER lumen (prevalent in muscle cells)

Question 27

Rough ER

Answer 27

ribosomes on outer surface produce proteins such as insulin and secrete into the bloodstream, proteins secreted by Rough ER called glycoproteins (proteins with carbohydrates covalently bonded to them), glycoproteins transported by transport vesicles; also produces membranes by adding proteins and phospholipids to membrane

Question 28

Golgi Apparatus

Answer 28

group of flatted membrane sacs (cisterns), has a cis face (located near the ER) for receiving and a trans face for shipping; products from the ER are modified and transported using vesicles, macromolecules are manufactured (ie;: pectin and other polysaccharides); molecular identification tags like phosphate group are added to Golgi products before shipping, vesicles carrying products may also have external molecules on their membranes as docking sites

Question 29

Lysosome

Answer 29

membranous sac of hydrolytic enzymes (made in rough ER) that hydrolyze macromolecules in the acidic environment of lysosomes; carry out intercellular digestion in 2 ways: phagocytosis (engulf smaller organisms or food particles) and autophagy (lysosomes fuse with intercellular materials that are surrounded by a membrane and recycle their nutrients)