Chapter 3 Cell terms and concepts

Question 1

main purpose of rough endoplasmic reticulum?

Answer 1

fold, package, and modify proteins

Question 2

main purpose of lysosomes?

Answer 2

contains digestive enzymes in order to break down viruses, bacteria, toxins, other cells, glycogen and other necessary molecules for cell excretion

Question 3

main purpose of peroxisomes and which type of cells are most likely to be found abundant?

Answer 3

neutralizes free radicals by converting them into hydrogen peroxide which catalases into water; usually found in liver or kidney cells to play role of detoxification

Question 4

main purpose of cytoskeleton?

Answer 4

supports cellular structure and allows for movement within it

Question 5

what is cytosol made up of?

Answer 5

viscous semitransparent fluid in cytoplasm containing proteins, sugars, salts, and other solutes

Question 6

function and structure of mitochondria

Answer 6

lozenge-shaped; source of ATP production; have “shelves” called cristae

Question 7

structure and function of ribosomes

Answer 7

contains proteins and rRNAs; synthesizes protein

Question 8

structure and function of mRNA

Answer 8

nucleotide strand that reflects exact nucleotide sequences of DNA and carry DNA’s message

Question 9

structure and function of glogi apparatus

Answer 9

system outside of endoplasmic reticulum which modifies proteins to export, and packages enzymes into lysosomes for cellular use; traffic director of proteins with use of vessicles

Question 10

necrosis

Answer 10

death or disintegration of cell caused by disease or injury

Question 11

what are microfilaments made of and what does it help construct

Answer 11

thin strand of protein actin; helps provide structure to cytoskeleton of cell by maintaining or changing its shape

Question 12

structure and function of endoplasmic reticulum

Answer 12

outside of nucleus; composed of cisterns; rough ER uses ribosomes to package proteins which will be transported to glogi apparatus; smooth ER contains enzymes that help break down lipids and glycogen and makes cholesterol and phospholipids

Question 13

structure and function of lysosomes

Answer 13

acidic sacs containing digestive enzymes in order to break down viruses, bacteria, toxins and dead cells; breaks down glycogen also

Question 14

structure and function of peroxisomes

Answer 14

neutralizes free radicals by converting them into hydrogen peroxide which catalases then convert to water; help detoxify in liver and kidney

Question 15

structure and function of intermediate filaments

Answer 15

tough protein fibers “woven ropes”; resist tension; attach to desmosomes to resist pulling forces on a cell

Question 16

microtubules functions and structure

Answer 16

hollow tubes made of protein tubulin; radiate from centrosome; organelles attach like ornaments hanging from branches; uses ATP to move organelles around

Question 17

what are centrioles

Answer 17

cylinders of microtubules; composed of nine sets of triplets of these microtubules

Question 18

how are cilia formed from centrioles and what do they function

Answer 18

centrioles travel and multiply under the plasma membrane and push out microtubules on the outside of plasma membrane in order to move substances along the outside of cell; (moving mucus along the cell wall)

Question 19

how are flagella formed from centrioles and what function do they serve for the cell?

Answer 19

centriole attaches to plasma membrane, microtubules project out longer than cilia; serve to provide movement for cell such as a sperm cell

Question 20

what purpose do microvilli serve and how are they both similar and different to cilia?

Answer 20

microvilli serve to increase surface area of a cell to increase absorption ability; similar in appearance to cilia, but cilia provides movement outside the cell while microvilli allows for nutrients to be absorbed more effectively

Question 21

structure and function of nuclear envelope

Answer 21

outside contains ribosomes, inside contains network of lamins which maintain shape of nucleus; contains nuclear poles (proteins) to channel material in and out

Question 22

nucleoli structure and function

Answer 22

centermost part of nucleus; contain parts to form ribosomes

Question 23

structure and function of chromatin

Answer 23

“beads on a string”; composed of DNA, histone proteins, and newly formed or formed RNA chains

Question 24

what phases is interphase composed of?

Answer 24

G1, S, and G2

Question 25

what happens in g1 phase of interphase

Answer 25

centrioles start to replicate in preparation for cell division but otherwise general normal cell activity occurs such as normal growing and synthesizing proteins

Question 26

what happens in S phase of interphase

Answer 26

DNA is replicated

Question 27

what happens in g2 phase of interphase

Answer 27

everything is finished being made to begin cell division such as enough DNA and both centrioles

Question 28

Describe DNA replication for the leading strand

Answer 28

enzyme helicase “unzips” DNA helix at the hydrogen bonds, enzyme RNA primase adds small section of nucleotides once at beginning in order to allow for enzyme DNA polymerase to add rest of corresponding nucleotides

Question 29

Describe DNA replication for the lagging strand

Answer 29

enzyme helicase “unzips” DNA helix at the hydrogen bonds, RNA primase adds multiple short sections of nucleotides which DNA polymerase then adds nucleotides in a reverse direction, these fragments are called Okazaki fragments, DNA polymerase then has to go back and change all the RNA primase nucleotides with its own, DNA ligase joins all these various attachments

Question 30

describe the process of prophase both early and late

Answer 30

early prophase includes chromatin coiling forming chromosomes, nucleoli disappears, miotic spindles form from microtubules, and propel centrosomes outwards.
late prophase includes nuclear envelope breaking, allowing microtubules to attach to the kinetochores of the centers of the chromosomes and begin pulling

Question 31

describe the importance of metaphase

Answer 31

all chromosomes are equally pulled by the centrosomes leaving them at the metaphase plate

Question 32

describe the significance of anaphase

Answer 32

centromeres of chromosomes split and the microtubules begin shortening at each of the centrosomes pulling each half of the chromosome

Question 33

describe the significance of telophase

Answer 33

prophase essentially in reverse

chromosomes begin to uncoil, new nuclear envelope forms, and nucleoli appear.

Question 34

describe interphase 1 of meiosis

Answer 34

maternal and paternal chromatids separate and coil and condense to form homologous pairs

Question 35

describe the significance of prophase 1 of meiosis

Answer 35

homologous chromosome pairs stick together and allow elements of each to trade place which greats variability of genes

Question 36

describe the similarities and difference between phases of mitosis and meiosis

Answer 36

DNA replication occurs in first stage of each’s interphase, but not in second stage interphase of meiosis
synapsis of homologous chromosomes occur only during prophase 1 of meiosis, allowing for crossover of genetic material
number of daughter cells in mitosis is two, but four genetically varied halves in meiosis
cells formed from mitosis help with tissue repair and human development where meiosis helps produce genetic variability and with the process of reproduction

Question 37

describe what DNA, mRNA, tRNA, and rRNA roles are in each phase of protein synthesis

Answer 37

in transcription: mRNA copies the coded information found in the DNA
in translation: rRNA found in ribosomes help code together the creation of proteins by housing mRNA and tRNA
the codon triplet will pair with the anticodon found on a coordinating tRNA along with the tRNA’s amino acid
as each new tRNA is matched to the mRNA sequence, a polypeptide chain is formed out of the tRNA’s amino acids

Question 38

hypertrophy

Answer 38

increase in fiber size

Question 39

hyperplasia

Answer 39

increase in fiber number

Question 40

atrophy

Answer 40

decrease of fiber size

Question 41

apoptosis

Answer 41

enzymes called caspases programs cell death