Chapter 7: Inside the Cell

Question 1

Compare and contrast structures are found in prokaryotic and eukaryotic cells.

Answer 1

Both: plasma membrane, DNA, RNA, ribosomes, flagella, cell wall and cytoplasm
P: Plasmid
E: chloroplast, lysosomes, cilia, rough/smooth endoplasmic reticulum, golgi apparatus, vacuole, mitochondria, nucleus

Question 2

contain chlorophyll; site of photosynthesis

Answer 2

chloroplasts, plant

Question 3

contain intracellular digestive materials

Answer 3

lysosomes. all.

Question 4

small, hairlike projections on the surface of the cell involved in movement.

Answer 4

cilia. animal

Question 5

studded with ribosomes; synthesizes proteins and
membrane molecules

Answer 5

rough endoplasmic reticulum. plant, animal, fungi

Question 6

stack of membranous sacs for processing proteins and lipids

Answer 6

golgi apparatus. animal, plant, fungi

Question 7

large fluid filled organelle most commonly found in plants; may be used for
storage of water, toxins, chemical defenses

Answer 7

vacuole. plant

Question 8

site of reactions of aerobic respiration: “powerhouse of cell”

Answer 8

mitochondria. plant, animal, fungi

Question 9

membrane -bound organelle containing cell’s genetic material

Answer 9

nucleus. plant, animal, fungi

Question 10

composed of subunits; responsible for protein synthesis

Answer 10

ribosomes. all

Question 11

lacking ribosomes; involved in synthesis of lipids, hormones, detoxification, or calcium storage depending on cell type

Answer 11

smooth endoplasmic reticulum. animal, plant, fungi

Question 12

external appendage allowing cellular movement

Answer 12

flagella. all

Question 13

provides structure to plant, fungal, and most bacterial cells

Answer 13

cell wall. bacteria, fungi, and plant

Question 14

composed of lipid bilayer and described as a ‘fluid mosaic’, serves to
surround the contents of the cell

Answer 14

plasma membrane. all

Question 15

small circular DNA found in many bacteria; can pass genetic information from one

Answer 15

Plasmid. bacteria

Question 16

Outline the benefits of compartmentalization in eukaryotic cells.

Answer 16

-increase surface area, enhances cellular respiration and ATP production

Question 17

Describe cytoskeleton

Answer 17

extensive system of protein fibers give cell structural support, and stability

Question 18

a) Describe the process of transporting molecules across the nuclear envelope.
b) Explain the purpose of molecular “zip codes” in protein transport.
c) Differentiate the transport of small molecules and large proteins through nuclear
pores.

Answer 18

a) MRNA or messengers of RNAs that were made in the nuclear carry info to build a proteins outside the nuclear envelope pore.
b) “nuclear localization signal” allows a protein to enter the nucleus by being given a short amino acid sequence
c) Small molecules can freely pass through nuclear pore while large proteins require specific transport carriers. (NLS)

Question 19

Explain the process of transporting molecules into and through the endomembrane
system. 3 steps

Answer 19

1. in the nucleus DNA used to make RNA which exits the nucleus and enters the cytoplasm of a cell
2. RNA attaches to ribosome that enters a rough ER, inside the ribosome: the message of the RNA is read and sequence of amino acids are put together, ultimately making a protein
3. the rough ER takes the protein, folds in secondary, tertiary structure and tags it (usually being carbs)
4. leaves rough ER and enter Golgi apparatus that tags protein w/other carbs or “tags” packed in a vesicle to be transported to: other organelle. plasma membrane for secretion, or lysosome

Question 20

First define exocytosis and endocytosis

Describe the 3 pathways used to recycle material via lysosomes.

Answer 20

Exoctyosis: material is exported in vesicles that fuse w/ plasma membrane and release contents outside of cell
Endocytosis: plasma membrane pinches in forming a vesicle that contains material from outside the cell
1. Receptor-mediated endocytosis:plasma membrane undergoes endocytosis to form a vesicle. Cargo is dropped in an organelle call early endosome, which acidifies it lumen, releasing cargo. Emptied cargo returned to plasma mebrane. Late endosome accept lysosomal enzymes from Golgi, maturing it into to a lysosome
2. Phagocytosis:plasma membrace surrounds smaller cells or food particle and “eat it”, forming a structure called phagososome. It deleivers to a lysosome to fuse, and concents are digested.
3. Autophology:encloses damaged organelle within membrance and forms an autophagosome, which delivers to a lysosome and is digested. Lysosome releases small molecules into cytosol

Question 21

Name the 3 major components of the eukaryotic cytoskeleton

Answer 21

Actin filaments
Intermediate filaments
Microtubes

Question 22

Descirbe structere and function of Actin Filaments (microfilaments)

Answer 22

• protein bound up in tertiary structure, but forms quaternary structure w/other actin in double helix formation
• maintain cell shape by resisiting tension (pull) and move cells via muscle contraction
• move organelles and cytoplasm in plants, fungi, and animals

Question 23

Describe stucture and function of Intermediate Filaments

Answer 23

-keratins/lamins fibers that wound into thick cables
-thicker, anchor organelles and nucleus
maintain cell shape by resisting tension (pull)

Question 24

Mictrotubes

Answer 24

-2 different proteins (a and b tubulin dimers) that form holow tube
help cell shape by resisting compression (push)
-move cells via flagella/cilia
-move chromoseome durnig cell division
-assist formation of cell plate
-tracks for itracellular transport

Question 25

Describe how structure of flagella relate to their function.

Answer 25

-Cilia and filagella share structure called an Axoneme: in this strucutre contains a motor protein called Dynein. With ATP, Dynein arms walk to minuse end and causes linked doublet to bend
(this rotates tail of sperm)

Question 26

Describe to process of motor protein: Kinesin

Answer 26

-kenisin grabs vesicles and bind it to its tail
-head of kinesin uses ATP to change formation allowing it to walk along microtubules

Question 27

Describe the process of motor protein: Myosin

Answer 27

-Myosin uses ATP to “head” of the protein to bend
-this pulls actin fiber
-muscle cell have a lot of actin and myosin , when flexed, pyosin proteins flex head to pull actin tight