Cellular Organelles and Mechanisms

Question 1

• cell’s fortification

- separates the interior of the cell from the outside environment

Answer 1

plasma membrane

Question 2

• cell’s environment

- fluid part enclosed by the membrane, contains organelles

Answer 2

cytoplasm

Question 3

• cell’s brain
• contains most of the genetic material, in the form of DNA
• control center of cell through gene regulation and expression
• sends instructions for building proteins by the messenger RNA (mRNA)

Answer 3

nucleus

Question 4

• cell’s pipe system
• system of metabolic processes (smooth), protein manufacturing ribosomes (rough)
• both smooth and rough function in glycosylation (addition of carb) of proteins and in the synthesis of lipids
• interconnected, flattened tubes that constitute the lumen, which sometimes expands into sacs called cisternae
• mostly surround nucleus

Answer 4

endoplasmic reticulum

Question 5

• cell’s delivery center
• tags vesicles and proteins to help them get carried to their correct destination
• 3 regions: cis is closest to ER, medial in the center, trans is nearest the plasma membrane

Answer 5

Golgi apparatus

Question 6

• cell’s anchor

- organizes and produces the microtubules of the cell’s cytoskeleton

Answer 6

centrosome

Question 7

• cell’s powerpoint
• produce energy for the cell, break down carbohydrates and some durations lipids to form molecule ATP
• membrane bound: outer is fairly smooth; inner is high convoluted, forming folds (cristae)
• lumen (space) known as the ________ matrix
• also contain circular DNA (mtDNA) and ribosomes for the production of RNA and some _______ proteins

Answer 7

mitochondria

Question 8

• cell’s factories
• translate RNA into proteins
• some are free in cytoplasm, some attached to ER
• composed of RNA and protein
• two parts, large and small subunit

Answer 8

ribosome

Question 9

• cell’s stomach
• vesicles filled with digestive proteins, can absorb something and break it down into recyclable pieces
• contains hydrolytic enzymes (acid hydrolases)
• acid internal pH of 5
• aid in cell renewal: digest food to make energy, clean up and recycle organelles
• digest invaders, taken up by the cell through endocytosis or phagocytosis
• budded into the cytoplasm by Golgi

Answer 9

lysosome

Question 10

• cell’s firemen
• vesicles that defend (or neutralize) the cell from free radicals
• contain oxidative and hydrolytic enzymes
• alpha oxidation of long chain FA’s, protect cell from own H2O2, break down H2O2 into water and oxygen, part of cholesterol and bile acid synthesis, part of synthesis of myelin

Answer 10

peroxisome

Question 11

• cell’s shapeshifter

- modifies the cell’s shape and ensures mechanical resistance to deformation

Answer 11

cytoskeleton

Question 12

• cell’s compartments

- enclosed storage vessels which are filled with water containing inorganic and organic molecules

Answer 12

vacuole

Question 13

• part of the nucleus
• fluid in which the chromosomes are found
• organized by the nuclear lamina, the protein scaffolding that is composed mainly of intermediate filaments

Answer 13

nucleoplasm

Question 14

• part of the nucleus

- site of ribosome production

Answer 14

nucleolus

Question 15

• involved in the production, transport, and post translational modification of proteins

Answer 15

rough endoplasmic reticulum

Question 16

• makes membranes

Answer 16

smooth endoplasmic reticulum

Question 17

• protons (H+) are pumped out of the mitochondrial matrix, creating an electrochemical gradient of protons
• the flow of protons back into the matrix drives the formation of ATP from carbohydrates and lipids

Answer 17

oxidative phosphorylation

Question 18

• when apoptosis is stimulated in a cell, proapoptotic proteins insert into the mitochondrial membrane, forming pores
• a protein known as _______ __, can then leave the inter membrane space of the mitochondria through the pores, entering the cytosol
• _______ __ in the cytosol stimulates a cascade of biochemical events resulting in apoptotic death of the cell

Answer 18

cytochrome c

Question 19

• mitochondrial disorder caused by defective mtDNA
• rare and results in paralysis of eye muscles and degeneration of the retina
• a single large deletion of mtDNA is responsible for the development of this syndrome

Answer 19

Kearns-Sayre syndrome

Question 20

• mitochondrial disorder that results in blindness, primary in young men
• a single change (point mutation) in mtDNA causes this disorder

Answer 20

Leber hereditary optic neuropathy

Question 21

• mitochondrial disorder where there are bone marrow and pancreas dysfunctions

Answer 21

Pearson syndrome

Question 22

• lysosomal storage disorder
• can be severe, with hearing loss and damage to central nervous system
• children stop developing between ages 2-4
• early-onset individuals have life span of 10-20 years
• glycosaminoglycans accumulate in the lysosomes “mucopolysaccharidoses”

Answer 22

Hunter and Hurler syndrome

Question 23

• most common lysosomal storage disease
• deficiency of glucosylcermidase and results in glucosylceramide lipidosis
• causes splenomegaly and bone pain

Answer 23

Gaucher syndrome (type I)

Question 24

• lysosomal storage disease

- ceramide accumulates as a result of acid ceramidase deficiency and is fatal within the first year of life

Answer 24

Farber disease

Question 25

• lysosomal storage disease
• accumulation of gangliosides in the brain owing to low activity or complete deficiency of lysosomal acid hydrolase β-hexosaminidase A
• accumulation occurs sooner or later in life depending on the extent of enzyme activity retained by affected person
• infantile form individuals usually die between 2-4
• juvenile form between 5-15 with progressive motor skill deterioration
• adult/late onset have speech/swallowing difficulties, cognitive decline, progressive neurological deterioration, psychiatric illness, and gait disturbances

Answer 25

Tay-Sachs disease