Midterm 1

Question 1

Vacuole?

Answer 1

Large vesicles derived from the ER and GA, membrane is semi-permeable
Storage of nutritious molecules, poisonous molecules, lytic enzymes, pigments, water

Question 2

prions vs Viroids

Answer 2

Prions: misfolded version of normal cellular protein, convert correctly folded proteins into prions (degenerative disease)
Viroids: infectious RNA molecules that replicate using plant host cell

Question 3

Tight junctions?

Answer 3

plasma membranes of adjacent cells are bound together by proteins
Prevents leakage of fluid through the epithelium layers impermeability
epithelial cells such as skin cells and enterocytes or endothelial cells such as blood vessel cells

Question 4

Gap junctions?

Answer 4

similar to plasmodesmata in plant cell
6 proteins (connexins) form a channel and allow the communication of adjacent cells.
letting through ions and small molecules

Question 5

Nucleus?

Answer 5

contains the genetic material in the form of Chromosomes
Surrounded by nuclear envelope/supported by nuclear lamina
Pore complexes regulate the entry and exit of nucleic acids and proteins

Question 6

what 2 organelles have a double membrane?

Answer 6

Mitochondria and chloroplasts

Question 7

Actual central dogma?

Answer 7

RNA to protein, can go RNA to RNA or RNA to DNA, or DNA to DNA or DNA to RNA

Question 8

Cellular respiration equation?

Answer 8

C6H12O6 + 6O2 —– 6CO2 + 6H2O + ENERGY

Question 9

Thykaloids?

Answer 9

membranous flat sacs inside chloroplast that are stacked, contain photosynthetic pigments (chlorophylls)
loat inside the stroma

Question 10

Peroxisome?

Answer 10

organelle that contains enzymes that remove hydrogen atoms from substrates and transfer them to oxygen
Breaks down fatty acids
Detoxifies

Question 11

Plant cell wall?

Answer 11

contains cellulose, create secondary cell wall for support and separation

Question 12

Lysosomes?

Answer 12

Digestive organelle that contains hydrolytic enzymes (digestion of macromolecules)
fusion of lysosomes with phagocytosis vesicles allow the digestion of preys or pathogens into simple sugars or amino acids

Question 13

Reproduction of prokaryotes vs eukaryotes?

Answer 13

Prokaryotes: asexual through binary fission into two identical daughter cells, 1 RNA polymerase
Eurkaryotes: sexual reproduction requiring meiosis and fertilization have diploid 2n and haploid n phases, 3 RNA polymerase

Question 14

Animal cell wall?

Answer 14

extracellular matrix, network made of glycoproteins, polysaccharides and proteoglycan
Collagen fibers are embedded
Integrins can transmit information between the ECM and the cytoskeleton

Question 15

Golgi apparatus?

Answer 15

Trafficking center: manufactures, receives, sorts, modifies, ships many molecules.
Vesicles arrive from the ER
Posttranslational modifications (PTMs). 88% of PTMs are either phosphorylation , glycosylation or acetylation

Question 16

Plammosdenta?

Answer 16

plants, neighbouring cells are connected by cytoplasmic channels that go through the cell walls, making the membrane continuous

Question 17

Centriole?

Answer 17

cylindrical structure in the centrosome of an animal cell composed of 9 microtubule triplets (“9+0 arrangement”)

Question 18

example of plasmosdenta?

Answer 18

Ex: Shortroot (Shr) protein: transcription factor responsible for the outwards cell division in the root.
Fluorescent DNA probe shows that Shr messenger RNA is only found in central stele cells
Fluorescently labelled proteins indicate that the Shr protein is present inboth stele cells (Ste) and endothelial cells (End in B) and is located in the nucleus
Shr proteins pass through plasmodesmata and reach the neighbouring cell layers

Question 19

Mich way does tubulin move?

Answer 19

Movements are caused by motor proteins powered by ATP
Kinesin move cargo towards the plus end
Dynein moves cargo towards the minus end

Question 20

Functions of the cytoskeleton?

Answer 20

network of microtubules, microfilaments, and intermediate filaments within the cytoplasm.
mechanical, structural, transport, motility and signalling functions.
It is responsible for the maintenance and modifications of the cell’s shape

Question 21

Mitochondria?

Answer 21

Double membrane-bound organelle that converts chemical energy acquired from the environment into chemical energy (ATP)

Question 22

What are microfilaments?

Answer 22

actin filaments: thin filaments composed of actin proteins acting alone or with myosin to cause cell contraction.
Double chain of actin subunits
Resist compression and maintains the shape of the cell

Question 23

What are only in eukaryotes?

Answer 23

Complex chromosomes
Complex membranous cytoplasmic organelles
Cytoplasmic organelles for aerobic respiration and photosynthesis
Proteins and filaments
Phagocytosis

Question 24

4 kinds of microscope? (LTSF)

Answer 24

Light Microscope
Transmission Electron Microscope
Scanning Electron Microscope
Flurorescence Microscope

Question 25

Prokaryates?

Answer 25

Absence of nucleus.
Presence of a nucleoid
Absence of organelles
The cytoplasm is therefore made of the cytosol
Flagellum

Question 26

What is archea?

Answer 26

prokaryotes that aren’t bacteria, extremophiles, many are methanogens (use CO2 and H2 to produce methane)

Question 27

Rough vs Smooth ER

Answer 27

Rough ER: ribosome-studded, synthesis of proteins that are secreted by the cell, translated into ER lumen
Membrane proteins inserted into ER membrane before sent to other areas of the cell
Smooth ER: ribosome-free and contains many enzymes
Synthesis of lipids, phospholipids, steroids, cholesterol, carbohydrate metabolism
Calcium storage in the sarcoplasmic reticulum of muscle cells

Question 28

What is the chloroplast?

Answer 28

organelle that converts solar energy acquired
from sunlight into chemical energy, converted by mitochondrion into energy (ATP)

Question 29

Photosynthesis euqation?

Answer 29

ENERGY + 6H2O +6CO2 —- C6H12O6 + 6O2

Question 30

What is a tubulin?

Answer 30

a dimer : ɑ-tubulin and β-tubulin.
has an orientation “plus end” and “minus end”
can grow and shrink in length from the “plus end” through polymerisation
minus end is attached to the centrosome

Question 31

Intermediate filaments?

Answer 31

strong and flexible filaments of intermediate size that provide mechanical support of the cell against physical stress,
only found in the cells of some animals, including vertebrates
more permanent
Can bear tension , maintain the shape of a cell and the nucleus and fix the position of organelles

Question 32

What is a microtubule?

Answer 32

thick hollow rod composed of tubulin proteins.

Question 33

What is the central dogma?

Answer 33

The sequential information is transferred from nucleic acid to nucelic acid or from nucleic acid to protein… but the transfer from protein to protein or protein to nucelic acid isnt possible

Question 34

centrosome?

Answer 34

structure present in the cytoplasm of animal cells that functions as a microtubule-organizing center

Question 35

Nucleous?

Answer 35

consisting of chromosomal regions
containing ribosomal RNA genes and proteins, site of of rRNA synthesis and ribosomal subunit assembly with the rRNA
Ribosomes then use mRNA to synthesize proteins

Question 36

Electron gradient?

Answer 36

diffusion gredient of an iron, affected by both the concentration difference of ion across membrane and ion’s tendency to move relative to the membrane potential

Question 37

Cilla/flagella?

Answer 37

have a core (axoneme) made of nine outer doublet microtubules and two inner single microtubules (“9+2” arrangement)
The sliding of microtubules onto each other depends on a motor protein (dynein)

Question 38

Desmosones?

Answer 38

anchors adjacent cells together through transmembrane proteins that are linked to the intermediate filaments.
keep adjacent cells tight together, especially in tissues that can stretch
Muscle celles (myocyte)

Question 39

Serial Endosymbiosis?

Answer 39

The mitochondrion originates from the phagocytosis of an aerobic bacterium by an archaea cell
The chloroplast originates from the phagocytosis of a photosynthetic bacterium by eukaryote.

Question 40

Eukaryotes?

Answer 40

The cytoplasm includes the cytosol, organelles (except the nucleus), and some inclusions
Presence of a nucleus with linear chromosomes, made of chromatin
Projects from cytoskeleton