A2.2 Cell Structure and B2.2 Organelles

Question 1

The function of unicellular organisms

Answer 1

-Unicellular organisms carry out all the functions of life such as metabolism, response to stimuli, homeostasis, growth, reproduction, nutrition, and excretion

Question 2

What do all cells have?

Answer 2

-All cells have a plasma membrane, DNA containing region and cytoplasm

Question 3

What do prokaryotes not have?

Answer 3

-a membrane bound nucleus

Question 4

What is the cell membrane also called?

Answer 4

-the phospholipid bilayer containing a hydrophilic head and a hydrophobic tail

Question 5

Surface area to volume in cells

Answer 5

-cells stay small to maintain a high SA to V ratio so that material can be more efficiently transferred in and distributed inside

Question 6

What do surface area and volume ratios control in the cell?

Answer 6

-heat production
-waste production
-resource consumption
-rate of exchange

Question 7

What are prokaryotes?

Answer 7

-smallest known cells, smallest being 5 micrometers
-can be bacteria or archaea
-differ in amino acids used to initiate protein synthesis

Question 8

What are characteristics of prokaryotes?

Answer 8

-most have a cell wall surrounding the plasma membrane
-many have a flagella (used for movement) and pili (used to attach to surfaces)
-cytoplasm with 70s ribosomes
-circular DNA that is concentrated in a nucleoid region and can have plasmids (circular satellite DNA)
-divides by binary fission

Question 9

What is a eukaryote?

Answer 9

-contains DNA with proteins (histones) which has instructions for generating proteins (building blocks)

Question 9

What is special about the nucleoid in prokaryotes?

Answer 9

-contains naked DNA which has instructions for proteins (building blocks)
-little to no protein (histones) to support DNA

Question 10

What is a nuclear envelope?

Answer 10

-double membrane with pores (proteins) that allow the flow of material in and out of nucleus

Question 11

What is the mitochondria and chloroplast?

Answer 11

-double layered membranes and they contain their down DNA (mtDNA inherited from maternal side in humans)
-mitochondria synthesizes ATP
-chloroplast contains chlorophylls that are essential in photosynthesis

Question 11

What is the endomembrane system, ER, golgi apparatus, and vesicles?

Answer 11

-they are organelles where lipids and new polypeptide chains are modified into final products

Question 12

What are lysosomes?

Answer 12

-type of vessicle that buds from the golgi membranes
-organelle of intracellular digestion (suicide cell)

Question 13

What are peroxisomes?

Answer 13

-sacs of enzymes that break down fatty acids (FA), alcohol, and amino acids

Question 14

What is the central vacuole?

Answer 14

-fluid filled storage sac with amino acids, sugar, ions, water, and toxic waste
-small in animals
-huge in plants

Question 15

What are microtubles?

Answer 15

-they are essential for cell shape, motion, growth, and structure of the flagella

Question 16

What are microfilaments?

Answer 16

-mesh like fibrous actin that contributes to cell shape and movements at the surface

Question 17

What is the cell wall?

Answer 17

-provides structure and support of plants and fungi
-plants = cellulose
-fungi = chitin

Question 18

What is cilia?

Answer 18

-contributes to cell movement, many motile structures that projects from the surface of the cells

Question 19

What is flagella?

Answer 19

-not as profuse as cilia but same function, contributes to cell movement

Question 20

What are pseudopods?

Answer 20

-they are essentially false feet, temporary lobes that bulge from cells, contributes to cell movement

Question 21

What about striated muscle is atypical?

Answer 21

-multinucleated due to fusion of cells

Question 22

What about fungal hyphae is atypical?

Answer 22

-cells usually separated by septa (dividing wall) but some are not have continuous cytoplasm

Question 23

What about the sieve tube cell is atypical?

Answer 23

-in phloem and may lack nuclei and organelles

Question 24

What about cell blood cells is atypical?

Answer 24

-lacks nucleus and cannot replicate

Question 25

What do animal cells have that no other cells have?

Answer 25

-centrioles and lysosomes

Question 26

What do plant cells have that other cells don’t?

Answer 26

-chloroplasts and plastids