Chapter 4

Question 1

Cell Theory

Answer 1

All organisms are composed of cells, cells are the basic units of structure and functions, cells come only from preexisting cells (self-reproducing)

Question 2

Surface-area-to-volume ratio

Answer 2

As cells increase size, surface area becomes inadequate to exchange materials (smaller size = goood)

Question 3

Prokaryotic Cells

Answer 3

Lack membrane-bound nucleus. Located in Bacteria and Archea domains

Question 4

Eukaryotic Cells

Answer 4

Posses a nucleus, belongs in Eukarya domain

Question 5

Cell envelope

Answer 5

Consists of plasma membrane, the cell wall, and glycolyx

Question 6

Plasma Membrane

Answer 6

Phospholipid bilayer embedded with proteins. Regulates entrance and exits of subtances

Question 7

Mesosomes

Answer 7

Found in prokaryotic cells, plasma membrane can form this. Increases internal surface area

Question 8

Cell Wall

Answer 8

maintains shape of the cells

Question 9

Glycocalyx

Answer 9

a layer of polysaccharides. If the layer is well organized it is called a capsule. Helps bacteria attach to surfaces

Question 10

Cytoplasm

Answer 10

A semifluid solution composed of water and inorganic and organic molecules encased by plasma membrane

Question 11

Ribosomes

Answer 11

Prokaryotic DNA synthesized on tiny structures. Still contain RNA and protein in two subunits.

Question 12

Cyanobacteria

Answer 12

Bacteria that is capable of photosynthesis in the same manner as plants

Question 13

Thylakoids

Answer 13

Chlorophyll and other pigments absorb solar energy for production of carbohydrates. Third membrane of chloroplasts

Question 14

External Structures of Prokaryotic

Answer 14

Flagella, Fimbriae, and Pili. Made up of protein

Question 15

Flagella

Answer 15

Pushes the cell forward, like a tail

Question 16

Fimbriae

Answer 16

Hairlike bristles that allow adhesion to surfaces

Question 17

Conjugation Pili

Answer 17

Rigid, tubular structures used by prokaryotes to pass DNA from cell to cell

Question 18

Organelles

Answer 18

Distingushes Eukaryotic and Prokaryotic cells, internal membrane-bound compartments

Question 19

Origin of Eukaryotic Cells

Answer 19

First cells were prokaryotics, then evolved to be Eukaryotic.

Question 20

Endosymbiotic Theory

Answer 20

Theory that states how Eukaryotic Cells came to be and the importance of mitochondria and chloroplasts origin

Question 21

Vesicles

Answer 21

Membranous sacs that enclose the molecules and keep them seperate from cytoplasm

Question 22

Cytoskeleton

Answer 22

Serves as ‘tracks’ for the vesicles. Similar to a 3D road system inside the cell

Question 23

Cellulose

Answer 23

Found in plant cells, therefore they have a different composition from the bacteria cell wall

Question 24

Nucleus

Answer 24

Essential to life and function of Eukaroytic cells. Contains genetic info (DNA)

Question 25

Nucleoplasm

Answer 25

Semifluid matrix found within the interior of the nucleus

Question 26

Chromatin

Answer 26

Combo of proteins and nucleic acids

Question 27

Chromosomes

Answer 27

Originated from Chromatin, but they coiled into rodlike structures. Carries DNA and Genes

Question 28

Nuclear Envelope

Answer 28

A double membrane which seperates the nucleaus and cytoplasm

Question 29

Nuclear Pores

Answer 29

Acts as gatekeepers to regulate what goes in and out

Question 30

Endomembrane System consists of

Answer 30

Nuclear envelope, membranes of endoplasmic reticulum, Golgi apparatus, and vesicles

Question 31

Endoplasmic Reticulum (ER)

Answer 31

System of membranous channels and saccules. Consists of smooth ER and rough ER

Question 32

Rough ER

Answer 32

Studded with ribosomes outside the membrane that faces cytoplasm. Can produce proteins. Form vesicles to transport

Question 33

Smooth ER

Answer 33

Does not have attached ribosomes. Increased smooth ER helps produced more lipids. Form vesicles to transport

Question 34

Golgi Apparatus

Answer 34

Made up of stacked, slightly curved, flattened succles. One side is directed towards ER, other side is directed towards plasma membrane. Vesicles from smooth / rough ER are received by Golgi.

Question 35

Lysosomes

Answer 35

Vesicles produced by Golgi. Assist in digestion material in cells into subunits that are exported or recycled

Question 36

Microbodies

Answer 36

Variety of membrane-bound vesicles within Eukaryotic cells. Contain special enzymes to preform specific functions (peroxisome)

Question 37

Peroxisome

Answer 37

Example of a microbody, a vesicle that break down fatty acids. Assistants to other organelles. Also found in plant cells, they can carry out an opposite reaction to photosynthesis

Question 38

Vacuoles

Answer 38

Membranous sacs that store substances. Mainly found in fat cells and are essential to plant function.

Question 39

Central Vacuole

Answer 39

In plant cells, can take up to 90% volume in the cell. Provides structual support and helps produce more cytoplasm with increased size.

Question 40

Chloroplasts

Answer 40

Uses solar energy to synthesize carbohydrates during photosynthesis. Has a 3 membrane system

Question 41

Mitochondria

Answer 41

Breaks down carbohydrates products to produce ATP during cellular respiration

Question 42

Stroma

Answer 42

A semifluid enclosed by a double membrane, found in chloroplasts.

Question 43

Plastids

Answer 43

Plant organelles that are surrounded by a double membrane with varied functions

Question 44

Mitochondira

Answer 44

Placed where energy is most needed. Have two membranes. Produce the most ATP

Question 45

Cristae

Answer 45

Inner membrane of mitochondria, encloses semifluid matrix

Question 46

Cytoskeleton importance

Answer 46

Cell shape, movement, internal transport. Contains filaments which help for shape and movement. Responds to change

Question 47

Actin Filaments

Answer 47

thin, flexiable fibers