Chapter 3

Question 1

cell theory

Answer 1

1. the functional unit of all organisms
2. all cells come from division of preexisting cells
3. cells are the smallest units that perform all vital physiological functions
4. each cell maintains homeostasis at the cellular level

Question 2

plasma membrane

Answer 2

outer boundary

Question 3

plasma membrane functions

Answer 3

1. physical boundary
2. regulation of exchange with environment
3. sensitive to the environment
4. structural support

Question 4

plasma membrane protein functions

Answer 4

1. anchoring proteins
2. recognition protein
3. enzymes
4. receptor proteins
5. carrier proteins
6. channels
7. gated channels

Question 5

plasma membrane components

Answer 5

plasma membrane lipids: phospholipid bilayer

membrane proteins:
integral proteins: cannot easily be separated from membrane
peripheral proteins: easily separated from membrane

Question 6

glycocalyx coating on surface of cells

Answer 6

made of proteoglycans, glycoproteins, and glycolipids
functions:
1. lubrication and protection
2. anchroing and locomotion
3. specificity in bidning (function as receptors)
4. recognition (immune response)

Question 7

cytoplasm

Answer 7

materials inside cell, but outside of nucleus

Question 8

cytosol

Answer 8

intracellular fluid, contains dissolved materials, such as nutrients, ions, proteins and waste products

Question 9

organelles

Answer 9

structures with specific functions

Question 10

inclusions

Answer 10

masses of insoluble material in cell, often stored nutrients such as glycogen granules or lipid droplets

Question 11

cytoskeleton

Answer 11

structural protein for shape and strength
–> microfilaments
–> intermediate filaments
–> microtubules

Question 12

microfilaments

Answer 12

thin filaments of protein actin
–> provide mechanical strength
–> adjust consistency of cytosol
–> interact with thick filaments of myson for muscle contraction
–> create microvilli

Question 13

intermediate filaments

Answer 13

durable, strengthen and stabilize tissues, cells and organelles

Question 14

microtubules

Answer 14

tubulin proteins attach to centrosome
move organelles within the cell with the help of motor proteins
form spindle apparatus to distribute chromosomes
form centrioles and cilia

Question 15

cilia

Answer 15

moves fluid across cell surface

Question 16

primary cilium

Answer 16

nonmotile (senses environmental stimulus)

Question 18

motile cilia

Answer 18

found on cells linign respiratory and reproductive tracts (9+2 array)

Question 19

flagellum

Answer 19

whip-like extension of cell membrane on the male sex cell

Question 20

centrioles

Answer 20

form spindle appartus during cell division

Question 21

Centrosome

Answer 21

cytoplasms next to the nucleus that surrounds centrioles

Question 22

ribosomes

Answer 22

protein synthesis
fixed ribosomes bound to RER; free ribosomes in cytoplasm

Question 23

proteasomes

Answer 23

hollow cylinders of proteolytic enzymes with regulatory proteins at their ends

Question 24

ER

Answer 24

storage chambers known as cisternae
1. synthesis of proteins, carbohydrates and lipids
2. storage of synthesized molecule and materials
3. transport of molecules within the ER
4. detoxifications of drugs or toxins

Question 25

what does smooth ER synthesize?

Answer 25

phospholipids and cholestrol (for membranes steroid hormones (for reproductive system) glycerides (for storage in liver and fat cells) glycogen (for storage in muscle and liver cells)

Question 26

RER

Answer 26

active in protein and glycoprotein synthesize folds proteins into secondary and teriary structures encloses products in transport vesicles for delivery to Golgi apparatus

Question 27

golgi apparatus

Answer 27

stacks of flattened membranes (cistern) containing chambers modifies and packages secretions for release from cell adds or removes carbohydrates to or from proteins renews or modifies the plasma membrane packages special enzymes within vesicles (lysosomes) for use in the cytoplasm

Question 28

lysosomes

Answer 28

powerful enzyme-containing vesicles produced by golgi apparatus vesicles containing digestive enzymes function: intracellular removal of damaged organelles or pathogens

Question 29

lysosome activation occurs when

Answer 29

(a) A primary lysosome fuses with the membrane of another organelle, such as a mitochondrion (b) A primary lysosome fuses with an endosome containing fluid or solid materials from outside the cell (c) The lysosomal membrane breaks down during autolysis following cellular injury or death

Question 30

autolysis

Answer 30

self destruction of damaged or inactive cells --> lysosome membranes break down --> digestive enzymes released --> cell is destroyed --> cellular materials are recycled

Question 31

peroxisomes

Answer 31

small enzyme containg vesicles break down organic compounds such as fatty acids produce the free radical hydrogen peroxide (H2O2) Catalase converts H2O2 to oxygen and water

Question 32

nucleus

Answer 32

control of metabolis, storage and processing of genetic information, control of protein synthesis and assembly of ribosomal subunits

Question 33

nuclear envelope

Answer 33

double membrane around the nucleus

Question 34

perinuclear space

Answer 34

between two layers of the nuclear envelope

Question 35

nuclear pores

Answer 35

communiation passages in nuclear envelope

Question 36

nuclear matrix

Answer 36

in the nucleoplasm and supports filaments

Question 37

nucleoli

Answer 37

nuclear organlles, synthesize rRNA and assmble ribosomal subunits made of RNA, enzymes and histones

Question 38

nucleosome

Answer 38

DNA coiled around histones, lightly coiled into chromatin in non-dividing cells, tightly coiled chromosoems form before division

Question 39

Process of transcription

Answer 39

RNA polymerase binding 1. RNA polymerase nucleotide linking ▪ Begins at “start” signal in promoter region ▪ Reads DNA code ▪ Binds nucleotides to form mRNA in three-base sequences known as codons 2. Detachment of mRNA ▪ Enzyme and mRNA strand detach from DNA at “stop” signal

Question 40

Process of Translation

Answer 40

– After leaving nucleus, mRNA binds to ribosomal subunits in cytoplasm – Each mRNA codon translates to one amino acid – Amino acids are delivered by transfer RNA (tRNA) – A tRNA anticodon binds to a complementary mRNA codon – Enzymes join amino acids with peptide bonds – At stop codon, components separate