Chapter 4 - Cells: The Working Units of Life

Question 1

of the following, which is enclosed in a membrane, and has the greatest amount of internal surface area? 
nucleus
endoplasmic reticulum 
mitchondria
chloroplast
ribosome

Answer 1

Endoplasmic reticulum

Question 2

what would be found at the top of a centrifugation gradient?

Answer 2

ATP molecules

Question 3

Prokaryotes

Answer 3

are surrounded by a cell membrane

Question 4

proteins are synthesized by _____ and the carbohydrates are added in the _____.

Answer 4

the rough endoplasmic reticulum and golgi apparatus

Question 5

T/F

DNA in the nucleus is packaged with several proteins

Answer 5

True

Question 6

Organelles that is involved in energy-transfer conversation

Answer 6

chloroplasts

Question 7

the presence of ____ means that substances must pass through, rather than between, the epithelial cells that form the lining of the small intestine

Answer 7

tight junctions

Question 8

how do biological membranes serve cells?

Answer 8

by being responsible for selective permeability, compartmentalization, interactions with other cells, and the surrounding environment

Question 9

phospholipid bilayer

Answer 9

prevents free passage of most materials across a membrane

Question 10

what does the movement of specific substances into or out of a cell often require

Answer 10

specific transporter proteins

Question 11

how does oxygen enter cells?

Answer 11

by simple diffusion

Question 12

how does glucose enter cells?

Answer 12

by facilitated diffusion relying on the participation of “transporter” proteins

Question 13

primary and secondary active transports move solutes in which way

Answer 13

against their concentration gradients

Question 14

what is required for primary active transport

Answer 14

direct ATP hydrolysis EX Na+K+ATPase

Question 15

energy moving “down” gradients provides energy transfers that drives

Answer 15

secondary active transport

Question 16

“saturation” of transport refers to what

Answer 16

solute movements that require transporter proteins, and occurs when all of these proteins are actively transporting their appropriate solute

Question 17

ribosomes

Answer 17

sites of protein synthesis, where the information encoded by nucleic acids directs the sequential linking of amino acids to form proteins

Question 18

cytoskeleton

Answer 18

collective name for filaments made up on polymers of monomer subunits that play roles in cell division or in maintaining the shapes of cells

Question 19

mitochondria

Answer 19

the powerhouse of the cell

Question 20

centrioles

Answer 20

are associated with nuclear division and formation of cells

Question 21

cell membrane

Answer 21

separates the cell from its environment and regulates traffic of materials into and out of the cell

Question 22

rough endoplasmic reticulum

Answer 22

the site of much protein synthesis, which occurs on ribosomes on its surface

Question 23

cell wall

Answer 23

in a plant cell

supports the cell

Question 24

ribosomes

Answer 24

assemble proteins

Question 25

smooth endoplasmic reticulum

Answer 25

proteins and other molecules are chemically modified

Question 26

chloroplasts

Answer 26

harvest the energy of sunlight to produce sugar

Question 27

golgi

Answer 27

processes and packages proteins
concentrates, packages, and sorts proteins before they are sent to their cellular or extracellular destinations
adds some carbs to pro
some polysaccharides for the plant cell wall are synthesized

Question 28

vacuoles

Answer 28

occur in many eukaryotic cells, but particularly those of plants and fungi
storage and structure reproduction and catabolism

Question 29

microtubules

Answer 29

long, hollow, unbranched cylinders that form rigid internal skeleton for some cells or cell regions
act as a framework along which motor proteins can move structure within the cell

Question 30

tight junctions

Answer 30

prevent substances from moving through spaces between cells EX: the epithelium of the urinary bladder contains tight junctions to prevent urine from leaking out into the body

Question 31

Desmosomes

Answer 31

hold adjacent cells together with stable protein connections, but materials can still move around in the extracellular matrix

Question 32

gap junctions

Answer 32

channels that run between membrane pores in adjacent cells, allowing substances to pass between ells.