Plant Cellular Respiration

Question 1

In plant metabolism, sugar can be in the form of ___ and ___.

Answer 1

sucrose
starch

Question 2

Disaccharide: _____
Polysaccharide: ______

Answer 2

sucrose
starch

Question 3

Sucrose consists of ___;
Starch consists of ____.

Answer 3

glucose + fructose
many glucose units

Question 4

Where does sucrose accumulate? Where is it transported after?

Answer 4

cytosol
heterotrophic sink tissues (roots, stems, tuber)

Question 5

What happens to starch during daytime?

Answer 5

stored at the vacuole; called “transitory starch” which is insoluble and dense.

Question 6

At night, what happens to the transitory starch?

Answer 6

subjected to degradation

Question 7

A part of a plant that produces or releases sugars, such as a leaf is called ___.

Answer 7

source

Question 8

A part of a plant that receives or stores sugars, such as seeds, fruits, flowers, roots, and storage organs are called ____.

Answer 8

sink

Question 9

What are photosynthates?

Answer 9

sucrose and starch

Question 10

What part of the plant transports photosynthates?

Answer 10

phloem

Question 11

During photosynthesis, the amount of photosynthates increases, which drives increased cellular metabolism and growth and development.

Answer 11

true

Question 12

What is the second most abundant polysaccharide next to cellulose?

Answer 12

starch

Question 13

Two types of starch

Answer 13

amylose
amylopectin

Question 14

Where is starch synthesized and stored?

Answer 14

synthesized in the chloroplast;
stored in the vacuole

Question 15

A type of starch that is linear; glucose units are connected by alpha - 1,4 glycosidic bond; has less than 1% branching.

Answer 15

amylose

Question 16

A type of starch that is branching; branching pattern is facilitated by alpha - 1,6 glycosidic bond; 5-6% branching.

Answer 16

amylopectin

Question 17

It is the reverse chemical reaction of photosynthesis.

Answer 17

cellular respiration

Question 18

What are the various substrates of plants to fuel cellular respiration?

Answer 18

1. disaccharides
2. organic acids: pyruvate, malate
3. phosphorylated sugar like triose phosphate
4. lipids and proteins

Question 19

What are the three main phases of cellular respiration?

Answer 19

1. glycolysis
2. TCA cycle/citric-acid cycle
3. oxidative phosphorylation

Question 20

The oxidation of sucrose can be grouped into 4 major processes. What are these?

Answer 20

1. glycolysis
2. oxidative pentose phosphate pathway
3. citric acid cycle
4. oxidative phosphorylation

Question 21

The process by which sugar is split to produce glucose is called ____.

Answer 21

glycolysis

Question 22

Where does glycolysis occur?

Answer 22

cytosol

Question 23

When O2 is unavailable for glycolysis, it is followed by ____.

Answer 23

fermentative pathway

Question 24

How does glycolysis in plants differ from animals?

Answer 24

variations in:
1. regulatory features
2. alternative enzymatic routes
3. a parallel partial glycolytic pathway in plastid

Question 25

What are the two pathways for splitting sucrose?

Answer 25

1. invertase pathway 2. sucrose synthase pathway

Question 26

Invertase pathway and sucrose synthase pathway: irreversible or reversible?

Answer 26

1. invertase pathway: irreversible 2. sucrose synthase pathway: reversible

Question 27

The existence of two different pathways that split sucrose and can replace each other without a clear loss in function is called ___.

Answer 27

metabolic redundancy

Question 28

What are the two phases of glycolysis?

Answer 28

1. initial phase 2. energy conserving phase

Question 29

What happens in the initial phase of glycolysis?

Answer 29

hexose is phosphorylated twice and split, which produces 2 triose-P. this consumes 2 – 4 ATPs/ sucrose unit.

Question 30

The initial phase of glycolysis includes 2/3 irreversible reactions, catalyzed by ___ and ___.

Answer 30

hexokinase, phosphofructokinase.

Question 31

What happens in the energy conserving phase of glycolysis?

Answer 31

nad+ is reduced to nadh via 3-phosphate dehydrogenase.

Question 32

Products of glycolysis

Answer 32

2 molecules of Pyruvate 2 molecules of CO2 2 molecules of NADH

Question 33

An alternative pathway for the oxidation of sugars.

Answer 33

oxidative pentose phosphate pathway

Question 34

Oxidative pentose phosphate pathway is carried out by the enzymes in ___ and ___.

Answer 34

cytosol and plastids

Question 35

Main idea of OPPP

Answer 35

glucose-p (hexose-p) is converted to ribulose-p (pentose-p); which is then converted to triose (g3p) to enter glycolytic pathway.

Question 36

Products of OPPP

Answer 36

1. CO2 2. NADPH 3. Pentose-p

Question 37

Roles of oxidative pentose phosphate pathway in plant metabolism

Answer 37

1. NADPH supply in the cytosol 2. NADPH supply in plastids 3. Supply of substrate for biosynthetic pathways

Question 38

Cytosolic reactions generate products that are transported into the mitochondria to feed the citric acid cycle. True or False?

Answer 38

true

Question 39

Fates of PEP: * Pyruvate → transported directly to mitochondrion via pyruvate dehydrogenase * Oxaloacetate → transported directly to mitochondrion; converted to malate via PEP carboxylase & malate dehydrogenase → OAA, pyr

Answer 39

true

Question 40

Oxidizes organic acid → CO2, and transfer electrons to reduce NAD+ and FAD → NADH & FADH2 respectively.

Answer 40

citric acid / tca / krebs cycle

Question 41

Where does citric acid cycle take place?

Answer 41

mitochondria

Question 42

TCA can oxidize amino acid, but fatty acid oxidation occurs in peroxisome in plants (vs. animal mitochondrion). True or False?

Answer 42

true

Question 43

What are the unique features in Plant TCA cycle?

Answer 43

1. ATP; animals: GTP 2. malic enzyme ; animals have none

Question 44

What are the major events that take place in citric acid cycle?

Answer 44

1. oxidation: OAA to citric acid 2. reduction: NAD to NADH and FAD to FADH2 3. phosphorylation (substrate-level): ATP 4. decarboxylation: CO2 is released

Question 45

Components of Mitochondrial ETC found in the inner mitochondrial membrane

Answer 45

1. protein complexes 2. mobile electron carriers 3. ATP synthase (complex v)

Question 46

The presence of __ and ___ are unique features of plant mitochondrial ETC.

Answer 46

1. alternative oxidase 2. NAD(P)H dehydrogenase

Question 47

A feature of plant mitochondrial ETC that is tightly bound to the inner mitochondrial membrane.

Answer 47

alternative oxidase

Question 48

Alternative oxidase transfers electrons from UQ → O2, which bypasses ___, generating ___ as a product.

Answer 48

cytochrome c oxidase; H2O

Question 49

Alternative oxidase: No proton translocation. True or False?

Answer 49

true

Question 50

A feature of plant mitochondrial ETC that is rotenone-insensitive and transfers electrons to UQ.

Answer 50

NAD(P)H dehydrogenase

Question 51

Where is NAD(P)H dehydrogenase located?

Answer 51

matrix and external sides of the inner membrane/ ~intermembrane

Question 52

What kind of membrane protein is NAD(P)H dehydrogenase?

Answer 52

peripheral membrane protein

Question 53

NAD(P)H dehydrogenase: No proton translocation. True or False?

Answer 53

true

Question 54

The mitochondrial ATP synthase is almost the same as chloroplast ATP synthase. True or False?

Answer 54

true

Question 55

Mitochondrial ATP synthase is also called as ___.

Answer 55

FOF1 – ATP synthase; Complex V

Question 56

What kind of membrane protein is mitochondrial ATP synthase?

Answer 56

peripheral membrane protein

Question 57

The F0 subunit of mitochondrial ATP synthase promotes ____; while The F1 subunit is the ____.

Answer 57

proton translocation catalytic portion

Question 58

F0 subunit of mitochondrial ATP synthase: Peripheral membrane protein. True or False?

Answer 58

integral membrane protein