Cells Flashcards

Question

Membranous organelles

Answer 1

Nucleus, mitochondria, lysosomes, peroxisomes, endoplasmic reticulum, and Golgi complex

Answer 2

Ribosomes, centrosomes, centrioles, proteasomes, basal bodies

Answer 3

Enclosed by two phospholipid bilayers that are perforated by nuclear pores. Houses genetic material. * Usually the largest organelle. * Most cells have one nucleus, but some are anucleate (mature RBCs) and some are multinucleate (muscle cells) * Nucleolus is where synthesis of ribosomes occur

Answer 4

is where synthesis of ribosomes occur

Answer 5

Normally, chromatin is not as tightly condensed as it can be (chromosomes are only in that X shape during cell division). This leaves the DNA accessible to molecules involved in transcription.

Answer 6

Rough and smooth ER are functionally different parts of the same network

Answer 7

* Enclosed by a single phospholipid bilayer. * Lacks ribosomes * Cisterns more tubular and branching * Synthesizes new lipids * Detoxifies alcohol and other drugs * sequesters & releases Ca2+ ions.

Answer 8

Enclosed by a single phospholipid bilayer. Parallel, flattened sacs covered with ribosomes. Continuous with outer membrane of nuclear envelope, a very large organelle! Synthesizes proteins that are packaged in other organelles or secreted from cell

Answer 9

Not enclosed by a lipid bilayer. They are small granules of protein and RNA -Found in nucleoli, in cytosol, and on outer surfaces of rough ER, and nuclear envelope They “read” coded genetic messages (messenger RNA) and assemble amino acids into proteins specified by the code

Answer 10

Some proteins will start being created in the cytosol, but need to end up somewhere else. Proteins have tags that ensure they get delivered to where they need to end up. Some may go to the Rough Endoplasmic Reticulum (RER), some may stay in the cytosol, and some may even go to the mitochondria, peroxisomes, and nucleus. If it has a tag for the Rough Endoplasmic Reticulum, it will head there to be processed (CO-TRANSLATIONAL TRANSLOCATION as shown above) or some will be relocated after translation finishes (POST-TRANSLATIONAL TRANSLOCATION).

Answer 11

post office of the cell Enclosed by a single phospholipid bilayer. This complex is a system of cisterns that synthesizes carbohydrates and puts finishing touches on protein synthesis -Sorts, tags, packages, and distributes the proteins and lipids from the endoplasmic reticulum. Think of it as a post office or distribution warehouse. Receives newly synthesized proteins from rough ER Sorts proteins, splices some, adds carbohydrate moieties to some, and packages them into membrane-bound Golgi vesicles

Answer 12

Enclosed by two phospholipid bilayers. Organelles specialized for synthesizing ATP, and it also stores Ca2+ ions. Surrounded by a double membrane -Inner membrane has folds called cristae -Spaces between cristae called -matrix -Matrix contains ribosomes, enzymes used for ATP synthesis, small circular DNA molecule -Multiple molecules of mitochondrial DNA (mtDNA) Considered an endosymbiotic organelle

Answer 13

Mitochondria (& chloroplasts) are thought to be the descendants of previously free-living prokaryotic cells. Mitochondria (and chloroplasts) are thought to have originally entered ancestral eukaryotic host cell via endocytosis.

Answer 14

1. Mitochondria possess their own DNA and ribosomes. 2. The mitochondrial genome only encodes 37 genes. 3. Mitochondria obtain 99% of their proteins from genes located within the ‘host’ cell nucleus. 4. Mitochondria self-reproduce by dividing within our cells (their division is somewhat autonomous).

Answer 15

Enclosed by single phospholipid bilayer. It contains hydrolytic enzymes that will digest endocytosed materials. - digest proteins, sugars, lipids, nucleic acids - The “garbage disposals” of cells - Very important in immunity, too! - Involved in autophagy.

Answer 16

Enclosed by single phospholipid bilayer. Peroxisomes resemble lysosomes but contain different enzymes and are produced by endoplasmic reticulum. * Use molecular oxygen to oxidize organic molecules * Creates and destroys hydrogen peroxide. * Neutralizes toxic compounds. * Synthesizes plasmalogen phospholipids found in the myelin coating of neuronal axons.

Answer 17

Not enclosed by a lipid bilayer Hollow, cylindrical organelle that disposes of surplus proteins -Contain enzymes that break down tagged, targeted proteins into short peptides

Answer 18

Not enclosed by a lipid bilayer. Centrioles are a short cylindrical assembly of microtubules. Two centrioles lie perpendicular to each other within the centrosome—small clear area in cell -Play important role in cell division -Form basal bodies of cilia and flagella

Answer 19

Not enclosed by a lipid bilayer *Provides scaffolding for maintaining cell shape. *Enables contraction of many cell types. *Provides tracks for molecular motors to run along. *Enables chromosome separation at mitosis.

Answer 20

These are not enclosed by a lipid bilayer. They can contain stored cellular products and foreign bodies phagocytized by the cell. They are not essential for cell survival Examples: glycogen granules fat droplets melanin pigment granules ribosomes globs of various materials proteasomes

Answer 21

Organelles work together to create a properly functioning cell. A good example of this is how cells make and process proteins. Insulin production uses mRNA copy of the gene, leaves nucleus to attach to a ribosome in the ER and reads the instructions to assemble protein (insulin). The insulin molecules are pinched off in vesicles and travel towards the Golgi apparatus to fuse with it and gets processed and packaged for release. The packaged insulin molecules are "pinched off" in vesicles from Golgi apparatus and move towards cell surface membrane. The vesicle then fuses with cell surface membrane and cell surface membrane opens to release insulin molecules outside.

Answer 22

Golgi apparatus -Alzheimer's -CDG syndrome Endoplasmic reticulum: -cystic fibrosis -ERSDs Nuclear envelope -Progeria -ED muscular dystrophy Lysosomes related organelles -LSD (Tay-Sachs disease) -Autoimmune diseases Mitochondria -Cardiomyopathy -Cancer -Diabetes mellitus and deafness Plasma membrane -Familial hypercholesterolemia Infectious diseases (HIV, shigella, etc.)

Answer 23

Defective dynein (motor protein in cilia) make cilia unable to beat properly. Cilia in embryonic cells help determine symmetry in development. Defective cilia lead to situs inversus, respiratory issues, and even infertility.

Answer 24

There are a number of mutations that can lead to cystic fibrosis. * Most mutations will generate a protein that is unable to leave the ER. * The ER has strict control mechanisms that prevents incorrectly folded proteins from leaving. * CF mutations can generate functional proteins that are only slightly misfolded (slightly bent the wrong way). * The ER will not let these proteins leave and degrade them. These proteins make the Cl- channels needed in the membrane

Answer 25

Hereditary disease in which chloride pumps fail to create adequate saline layer on cell surface Thick mucus plugs pancreatic ducts and respiratory tract *Inadequate digestion of nutrients and absorption of oxygen *Chronic respiratory infections *Life expectancy of 30

Answer 26

Results from mutations in genes that code for proteins essential for the formation of ribosomes. The mutations lead to a reduced production of rRNA which may lead to apoptosis of certain cells (dealing with facial development).

Answer 27

This is a rare disorder from mutations in mitochondrial DNA. Mitochondrial disorders impact a lot of different areas of the body as mitochondria is involved in ATP generation in all cells. * MELAS is named for the different presentations like Mitochondrial Encephalopathy, Lactic Acidosis, and Stroke-like episodes. * Very noticeable in muscles and nervous system. * Accumulation of lactic acid in the blood, spinal fluid, brain. * Symptoms include seizures, headaches, recurrent vomiting, muscle weakness, dementia.