Cell Biology Lecture 17-22

Front 1

loss of electrons

Back 1

oxidation

Front 2

Gain of electrons

Back 2

Reduction

Front 3

A stage of the catabolism of glucose
Takes place in the cytosol, leads to formation of Pyruvate

Back 3

Glycolysis

Front 4

A stage of catabolism of glucose.
Occurs in the mitochondria of eukaryotic cells, leads to the oxidation of carbon to carbon dioxide

Back 4

Krebs cycle (or tricarboxylic cycle)

Front 5

a coenzyme that acts as an oxidizing agent

Back 5

NAD+

Front 6

accepts electrons from other molecules and gets reduced

Back 6

oxidizing agent

Front 7

a strong reducing agent that can donate electrons to other molecules

Back 7

NADH

Front 8

electrons are transferred from NADH by a series of membrane imbedded electron carriers. They move from lower free energy states and are passed on to molecular oxygen, reducing it to H2O

Back 8

Electron transport chain

Front 9

energy released during electron transport creates ATP by this..

Back 9

Oxidative phosphorylation

Front 10

In respiring cells most ATP synthesis occurs due to the electrochemical gradient that gets generated across the IMM by using the energy of NADH and FADH2 formed from breakdown of energy rich molecules (eg. glucose)

Back 10

The chemiosmotic hypothesis

Front 11

requiring free oxygen

Back 11

aerobic

Front 12

requiring an absence of free oxygen

Back 12

anaerobic

Front 13

class of molecules whose molecules can form channels through cell membranes

Back 13

porin

Front 14

Directly involved in photosynthesis, the site of CO2 reduction and assimilation into carbohydrates, amino acids, fatty acids, and terpenoid compounds

Back 14

Chloroplasts

Front 15

Membrane containing porins

Back 15

Chloroplast outer membrane

Front 16

Photosynthetic machinery on a system of flattened membrane sacs inside a chloroplast

Back 16

Thylakoids

Front 17

Stacks of thylakoids

Back 17

Grana

Front 18

unstacked thylakoids that connect grana

Back 18

Stroma Thylakoid

Front 19

space inside thylakoid

Back 19

lumen

Front 20

Outside thylakoid and inner envelope; contains proteins responsible for carb synthesis
- rich in proteins and ribosomes

Back 20

Stroma

Front 21

Membrane that has high galactose-containing glycolipids, very fluid, allows lateral diffusion of proteins

Back 21

thylakoid membrane

Front 22

A reaction where solar energy is absorbed & stored in ATP (cells primary source of chemical energy) and NADPH (main source of reducing power)

Back 22

Light dependent

Front 23

a reaction where carbohydrates synthesized from CO2 using energy from ATP/NADPH

Back 23

Dark reactions

Front 24

Most important light absorbing pigment
- molecule contains Mg2+ held in a porphyrin ring
- phytol chain embeds pigment in bilayer
- strongly absorbs violet, blue & red

Back 24

Chlorophyll

Front 25

most efficient pigment in promoting photosynthesis

Back 25

Chlotophyll-a

Front 26

a class of mainly yellow, orange, or red fat-soluble pigments, including carotene, which give color to plant parts

Back 26

carotenoids

Front 27

A system that harvests light of various wavelengths & transfers excitation energy to the reaction center

Back 27

Antenna system

Front 28

aid in unfolding polypeptides in the cytosol and folding proteins inside the chloroplast

Back 28

chaperones

Front 29

Protein targeted to chloroplasts/ subdomain that has a removable N-terminal peptide sequence
Protein remains in stroma after removal of STD

Back 29

stroma targeting domain (STD)

Front 30

Protein targeted to chloroplasts/ subdomain that has a removable N-terminal peptide sequence
Proteins move into thylakoid membrane or through it into the thylakoid lumen

Back 30

Thylakoid transfer domain (TTD)

Front 31

A small organelle that is present in the cytoplasm of many cells and that contains the reducing enzyme catalase and usually some oxidases.
- oxidation of toxic molecules

Back 31

peroxisome

Front 32

Stroma-containing tubule formed from plastids (most commonly leucoplast and chromoplasts)

Back 32

Stromule

Front 33

any of a class of small organelles, such as chloroplasts, in the cytoplasm of plant cells, containing pigment or food.

Back 33

Plastid

Front 34

- extensions of peroxisomes
- often directed towards chloroplasts
- formed rapidly in response to oxidative stress

Back 34

Peroxules

Front 35

Mitochondrial entensions, induced rapidly, involve dynamic related proteins that tubulate & constrict membranes

Back 35

Matrixules

Front 36

organelles that multiply by growth and division and are inherited in much the same way as the nucleus

Back 36

autonomous organelles

Front 37

group of organelles that is derived from an autonomous organelle and cannot take care of its individual inheritance

Back 37

Endomembrane Compartment

Front 38

A biosynthetic pathway where materials are transported in secretory vesicles & continuously discharge into extracellular space

Back 38

Constitutive secretory pathway

Front 39

A biosynthetic pathway in which materials are stored as membrane-bound packages that are discharges only in response to a specific stimulus

Back 39

Regulated secretory pathway

Front 40

uptake/recycling- works in inward direction
-materials move from outer cell surface to cytoplasmic organelles

Back 40

Endocytic pathway

Front 41

ability to transport a synthesized protein to a specific desination within the cell

Back 41

Intracellular Protein transport

Front 42

uses radioactive isotopes (R) & photographic emulsion
- short incubation with R (pulse)
- incubation with non-R (chase)

Back 42

Autoradiography & pulse-chase

Front 43

a fluorescent protein fused to DNA encoding protein to be studied

Back 43

Fusion Protein

Front 44

Change colour upon exposure to light of a specific wavelength
- photo-inducible proteins
- photo-convertible proteins

Back 44

Optical highlighter proteins

Front 45

the beaking up of cells for isolating organelles - subcellular fractionation

Back 45

Cell homogenization

Front 46

do not contain whole cells

Back 46

Cell free systems

Front 47

gene disruption; RNA interference

Back 47

mutant analysis

Front 48

presence of ribosomes bound to its cytosolic surface, network of flattened sacs (cisternae) continuous with the outer membrane of the nuclear envelope (peri-nuclear ER)

Back 48

RER (rough endoplasmic recticulum)

Front 49

lacks associated ribosomes, curved, higher tubular elements; smooth vesicles

Back 49

SER (smooth endoplasmic recticulum)

Front 50

DNA -> RNA / mRNA

Back 50

Transcription

Front 51

a complementary copy of one of the 2 DNA strands that make up a gene
Serves as a template to direct amino acid assembly
Mobile nucleic acid that can leave the nucleus and go into the cytoplasm

Back 51

mRNA

Front 52

RNA -> protein polypeptide

Back 52

Translation

Front 53

multiple ribosomes attach along an mRNA

Back 53

polysome

Front 54

groups of 2-4 hourglass shaped protein-lined channel in RER membrane
- ring of 6 hydrophobic amino acids at centre of pore/channel
- pore can be plugged by a short helical plug

Back 54

translocon

Front 55

a G-protein that binds to the signal sequence on a polypeptide- translation stops

Back 55

Signal recognition particle (SRP)

Front 56

multi-enzyme system (IMPs of ER) situated close to translocon
- addition of oligosaccharide chains to proteins to form glycoproteins

Back 56

Glycosylation

Front 57

a molecular chaperone that resides in ER lumen & folds protein into correct tertiary structure

Back 57

BiP and calnexin

Front 58

enzymatic protein processing in ER lumen form/ rearrange disulfide bonds

Back 58

Protein disulfide isomerases (PDIs)

Front 59

Transfer phospholipids between leaflets in a membrane

Back 59

Flippases

Front 60

short chains of sugar monomers linked to form an oligomer

Back 60

oligosaccharide

Front 61

vesicles form in regions of the RER that lack ribosomes

Back 61

exit sites or transition elements

Front 62

region between ER and Golgi complex
- transport vesicles fuse to form larger vesicles & interconnected tubules (VTCs)

Back 62

ER- golgi intermediate compartment (ERGIC)

Front 63

transport vesicles fuse to form larger vesicles & interconnected tubules

Back 63

vesicular-tubular clusters (VTCs)

Front 64

each cisterna physically moves gradually from the cis to the trans end of the golgi stack and finally disperses at the TGN

Back 64

Cisternal Maturation Model

Front 65

cisternae of a stack remain in place as stable compartments while cargo is shuttled through the stacks (from CGN to TGN) in vesicles that bud off from one membrane comparment and fuse with the next compartment

Back 65

Vesicular transport model

Front 66

Protein coat
- mechanical device for vesicle formation through membrane curvature during budding
- mechanism for selecting and concentrating material to be carried by the vesicle

Back 66

COP

Front 67

coated vesicle that transports cargo from the ER to the ERGIC and to the golgi complex, forward direction between golgi cisternae anterograde movement
- assembly depends on Sar1-GTP (secretion associated Ras-reated protein)

Back 67

COPII

Front 68

coated vesicle transport cargo within the golgi (trans->cis) and from the golgi back to the ER; retrograde movement
- assembly depends on ARF1-GTP (ADP ribosylation factor 1)

Back 68

COPI

Front 69

cargo vesicle that moves cargo from the TGN to endosomes, lysosome and vacuoles
forms a triskelion shape

Back 69

CCV (clathrin coated vesicle)

Front 70

'cell eating' brings in relatively large materials into a cell by wrapping around the material and enveloping it

Back 70

phagocytosis

Front 71

the taking in of matter by a living cell by invagination of its membrane to form a vacuole

Back 71

endocytosis

Front 72

brings a small volume of extracellular fluid and the materials suspended in it into the cell

Back 72

pinocytosis

Front 73

non-specific uptake, recycles membrane fraction between PM and intracelullar compartments

Back 73

bulk-phase endocytosis

Front 74

depends on receptors which binds to and hold specific molecules

Back 74

Receptor-mediated endocytosis

Front 75

an organelle in the cytoplasm of eukaryotic cells containing degradative enzymes enclosed in a membrane

Back 75

Lysosome

Front 76

organelle turnover
Lysosome fuses with ER-derived autophagic vacuole (autophagosome) to form autophagolysosome

Back 76

Autophagy

Front 77

fluid-filled, membrane-bound organelles in plants and yeasts

Back 77

vacuoles

Front 78

large protein complexes in both nucleus & cytoplasm, function to degrade large proteins into small peptides through breaking bonds tagged by the protein ubiquitin

Back 78

proteosomes

Front 79

small, highly conserved protein of 76 amino acids
plays a role in the degradation of defective and superfluous proteins

Back 79

ubiquitin

Front 80

programmed cell death to eliminate damaged cells, and for embyro development

Back 80

apoptosis

Front 81

flattened membrane-bounded compartments as found in the endoplasmic recticulum or golgi apparatus

Back 81

Cisterna