A2.2.4-6 - Cell structures & Functions

Question 1

what do all cells contain

Answer 1

DNA
a cytoplasm
a plasma membrane (semipermeable membrane made of fats)
ribosomes

Question 2

characteristics of prokaryotes (in comparison to eukaryotes)

Answer 2

no compartmentalization
no nucleus
no membrane bound organelles

has a nucleoid
evolved first
most are single celled

Question 3

What does DNA look like in prokaryotes

Answer 3

DNA is in a single loop, free floating in cytoplasm w/o protein/naked (histones)

Question 4

size of ribosomes in prokaryotes

Answer 4

70s

Question 5

approximate size of prokaryotes (archaea, bacteria)

Answer 5

10 nm

Question 6

similarities of prokaryotes and eukaryotes

Answer 6

both has plasma membrane, cytoplasm and free ribosomes

eukaryotic plant cells and prokaryotes both have cell walls

Question 7

characteristics of eukaryotes (in comparison to prokaryotes)

Answer 7

Larger, more complex
has membrane bound organelles

has a nucleus and membrane bound organelles

evolved from prokaryotes

Question 8

examples of single celled eukaryotes

Answer 8

amoebas, yeast

Question 9

examples of complex multicellular organisms (made up of multiple eukaryotic cells)

Answer 9

humans, plants, animals

Question 10

What does DNA look like in eukaryotes

Answer 10

DNA is wrapped around proteins contained in nucleus (seperate from the cytoplasm)

Question 11

size of ribosomes in eukaryotes (and where it can be found)

Answer 11

80s, both free floating in the cytoplasm and attached to RER

Question 12

size range of eukaryotes

Answer 12

5 -100 nm, but usually bigger than 10nm

Question 13

what are the importance of compartmentalization

Answer 13

it enables different chemical reactions to be separated, which is especially important when its adjacent chemical reaction is incompatable

it also allows chemicals for specific rxn to be isolated, which can increase efficiency

Question 14

cytoplasm function

Answer 14

it dissolves nutrients and chemicals needed for the cell to function
it transports materials around the cell
it provides a medium where chemical reactions can happen

Question 15

DNA (or RNA in some) function

Answer 15

it contains info for cells to function and grow
it contains instructions for building polypeptides (building blocks of proteins made up of chains of amino acids)

Question 16

what type of cell wall is present in plants

Answer 16

cellulose

Question 17

what type of cell wall is present in fungi

Answer 17

chitin

Question 18

vacuoles in plants, fungi and animals

Answer 18

plants- large and central and can take water
fungi, animals- small, scattered

Question 19

plastids (structure related to metabolism and storage) in animals, fungi, plants

Answer 19

plants- contains a type of plastid called a chloroplast that can photosynthesize
animals, fungi- no plastids, they must consume other animals, making them heterotrophs

Question 20

centrioles in plants, fungi, animals

Answer 20

animals- yes (mitosis)
plants, fungi- no

Question 21

flagella/cillia in plants, animals, fungi

Answer 21

plants- no
animals, fungi - some cells

Question 22

define gene

Answer 22

section of DNA that code for polypeptides

Question 23

Define gene expression

Answer 23

the process by which info from gene is used to create a functional product, usually a protein

Question 24

functions of proteins

Answer 24

-enzymes
-cell signaling
-structural support

Question 25

What are the cell walls of prokaryoties made of

Answer 25

a carbohydrate-protein complex called peptidoglycan

Question 26

What is the additional layer outside of the cell wall present in some prokaryotes

Answer 26

a polysaccharide layer called the capsule

Question 27

what is the function of the capsule layer in prokaryotes

Answer 27

it makes it possible for some bacteria to adhere to structures such as teeth, skin and food

Question 28

What is one major way to classify bacteria

Answer 28

is by their ability to retain a dye called crystal violet (purple appearance)

Question 29

What type of bacteria takes on a violet or blue appearance when exposed to crystal violet dye

Answer 29

gram positive bacteria, and contrastingly, gram negative bacteria do not retain this dye -> do not appear violet or blue when examined with a microscope

Question 30

Thickness of the peptidoglycan layer in a gram positive vs gram negative bacteria

Answer 30

gram positive bacteria have a significantly thicker peptidoglycan than gram negatives

Question 31

examples of gram positive bacteria

Answer 31

Bacillus and Staphylococcus

Question 32

what is the name of the hair like growths on the outside of the cell wall present in some bacterial cells

Answer 32

pili (pilus for plural)

Question 33

function of pilus

Answer 33

can be used for attachment, but their main function is in joining bacterial cells in preparation for the transfer of DNA from one cell to another (sexual reproduction)

Question 34

main function of flagella

Answer 34

flagella allow a cell to move

Question 35

what is the flagella anchored to

Answer 35

they are anchored to the cell wall and plasma membrane

Question 36

Does the cytoplasm occupy the complete interior of the cell

Answer 36

yes

Question 37

What are the most visible structures of the cytoplasm underneath a high magnification

Answer 37

chromosome or a molecule of DNA

Question 38

are there specialized areas within the cytoplasm in prokaryotes

Answer 38

no because internal membranes do not exist (the opposite is true for eukaryotes). all the cellular process taking place within prokaryotic cells occur within the cytoplasm, without the existence of specialized components

Question 39

What does a large amount of ribosomes present imply

Answer 39

they produce a substantial amount of protein

Question 40

what does it look like when large amount of ribosomes are present in a prokaryote under a Transmission Electron Microscopy (TEM)

Answer 40

they give a granular appearance

Question 41

What are plasmids

Answer 41

A component that a bacteria may contain, and these small, circular. They are small portions of the DNA that is transferable to other cells

Question 42

Are plasmids independent to the DNA

Answer 42

Yes, they are not connected to the main bacterial chromosome and they replicate independently of the chromosomal DNA

Question 43

Why do some bacterial cells have plasmid

Answer 43

plasmid DNA is not required by the cell under normal conditions, but it can help the cell adapt to unusual circumstances

Question 44

what type of genes do plasmids carry

Answer 44

Plasmids usually carry non-essential genes — such as antibiotic resistance or toxin production — that give the cell an advantage under stress or unusual conditions.

Question 45

how do bacterium acquire pladmids

Answer 45

bacterium may already carry (through inheritance) or acquire from its environment.

Question 46

What type of cells have large numbers of mitochondria

Answer 46

cells that have high energy requirements

Question 47

What is the loss/lack of reproductive ability related to + an example of this

Answer 47

increased specialization to carry out certain functions, an example is the human RBC, which do not have nuclei as they are specialized to transport respiratory gases

Question 48

In what form does DNA occur in eukaryotes

Answer 48

chromosomes, which vary in number depending on the species

Question 49

what does chromosomes look like when they are not dividing

Answer 49

they are notpresent as visible structures

Question 50

do plant or fungal cells have centrioles

Answer 50

NO!

Question 51

similarities b/w prok vs eurk

Answer 51

both have some outside boundary that involves a plasma meb both conduct all the functions of life DNA is present in both