Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

PLS 002A > Midterm 2 Study Guide > Flashcards

Midterm 2 Study Guide Flashcards

1
Q

What are the two phases in photosynthesis?

A

Light dependent reactions
Carbon-linked/light independent reactions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Which pigments participate in photosynthesis?

A

Chlorophylls and carotenoids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are carotenoids’ role in photosynthesis?

A

They transfer light energy to special pigments called reaction center chlorophylls

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Light-harvesting complexes

A

Structures with photosynthetic pigments that make up photosystems

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Why are carotenoids useful in photosynthesis?

A

Because they broaden the usable range of wavelengths a plant can absorb for photosynthesis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Light-dependent reactions

A

Use light energy to drive the synthesis of ATP and NADPH in an endergonic (energy-requiring) process

Occur in thylakoids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Carbon-linked/light independent reactions

A

Use chemical energy (ATP, NADPH) to drive the endergonic incorporation of CO2 into carbohydrates

Occur in the stroma (the colorless fluid surrounding the thylakoids inside a chloroplast)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is the final electron acceptor in photosynthesis?

A

NADP+, which is reduced to NADPH

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What molecule donates an electron to the ETC (electron transport chain) in photosynthesis, and what is this process called?

A

Water (H2O) is oxidized, also known as photolysis of water

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Why did Photosystem II evolve later than Photosystem I?

A

Because there was a need for an alternative source of electrons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

How is ATP synthesized?

A

ATP synthase couples the movement of H+ protons down their electrochemical gradient (which was created by the ETC) to phosphorylate ADP into ATP

Basically, there is a high concentration of protons in the lumen. These protons want to move to an area of lower concentration, i.e., the stroma. The movement of H+ protons to an area of lower concentration is used by ATP synthase to generate mechanical energy, which it uses to synthesize ATP

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is the first stable product of the Calvin cycle (in photosynthesis)?

A

3-PGA (3-phosphoglycerate)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What are the 3 important chemicals in the Calvin cycle?

A

RuBP (ribulose-1,5-bisphosphate)
3-PGA (3-phosphoglycerate)
G3P (glyceraldehyde-3-phosphate)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

How does the Calvin cycle work?

A

RuBP, CO2, and H2O are used to produce 3-PGA, which is then reduced to form G3P.

For every 3 RuBP molecules, one G3P molecule is produced. Multiple G3P molecules are then synthesized into sucrose.

The rest of the G3P molecules are recycled back into RuBP.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

How does light intensity affect plant development?

A

Plants become acclimated to light intensity, producing sun/shade leaves

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Shade leaves (as compared to sun leaves)

A

Thinner, higher leaf area, more thylakoids per chloroplast, and more photosystems

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Photorespiration

A

When the Rubisco enzyme acts on oxygen instead of carbon dioxide, producing one 3PGA molecule instead of two

This is an inefficient use of energy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is unique about CAM plants?

A

In CAM plants, CO2 fixation and the Calvin cycle are temporally separated
During the day, their stomata are closed
During night, their stomata open

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Why is the CAM mechanism useful?

A

Plants lose water through open stomata, so in hot climates, plants with closed stomata during the day save water

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

How does the CAM mechanism work?

A

At night, CO2 is fixed by PEP carboxylase into malate
During the day, that malate releases CO2, which is then fixed by Rubisco

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Difference between C4 and CAM plants

A

C4 plants have spatial separation, CAM plants have temporal separation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Which carboxylating enzymes do C3, C4, and CAM plants use?

A

C3 plants only use Rubisco whereas C4 and CAM plants use PEP carboxylase then Rubisco

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Compare C3, C4, and CAM plants’ energy requirements

A

From least to most energy required: C3, C4 and CAM

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Compare C3, C4, and CAM plants’ transpiration rates

A

From lowest to greatest transpiration rate: CAM, C4, C3

CAM plants are most water-efficient

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What is aerobic respiration?

A

The release of chemical energy stored in carbohydrates; cellular respiration in the presence of oxygen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Where does glycolysis (part of respiration) occur and what does it produce?

A

It occurs in the cytosol and produces 4 ATP, 4 NADH, and 4 pyruvate molecules

27
Q

What does the TCA/Krebs cycle (part of respiration) produce?

A

3CO2, 1 ATP, 4 NADH, 1 FADH2

28
Q

What is the use of NADH and FADH2?

A

They are used to donate electrons to the ETC (electron transport chain)

29
Q

What is the final electron acceptor in aerobic respiration?

A

O2, which is reduced to H2O

30
Q

What is the most efficient way to determine the rate of respiration?

A

To measure the amount of CO2 produced

31
Q

How does respiration occur in the absence of oxygen (anaerobic respiration)?

A

Instead of transporting pyruvate molecules to the mitochondria, glycolysis converts them into either lactic acid or ethanol.

This process is known as fermentation and produces very little ATP compared to aerobic respiration

32
Q

What are the four groups of primary metabolites?

A

Amino acids
Fatty acids
Carbohydrates
Nucleobases

33
Q

Where are fatty acids synthesized?

A

In plastids, or within chloroplasts in photosynthetic tissues

34
Q

What kind of reaction is fatty acid synthesis?

A

An overall reduction reaction, which requires a significant amount of reducing power in the form of NADH

35
Q

What are free fatty acids and what does the cell do to them?

A

They are very reactive molecules. The cell adds them to glycerol to reduce their reactivity (esterifying them)

36
Q

Esterification reaction

A

When an acid and alcohol are joined by an ester bond

37
Q

Triacylglycerols

A

Used as carbon storage by plants and can mostly be found in seeds

38
Q

Diacylglycerols

A

Have a polar (hydrophilic) head & make up membranes (e.g., phospholipids).

39
Q

Proteins

A

Long, unbranched chains of amino acids linked together by peptide bonds

40
Q

How are peptide bonds formed?

A

Through dehydration reactions

41
Q

Examples of PNPs

A

Allelopathic phytoxins, phytoalexins, repellants, toxins, attractants, hormones, and more

(you don’t have to memorize all of these, but you should know one when you see one)

42
Q

Terpenoids

A

Derived from isoprene (5-carbon unit). Mostly multicyclic C structures with oxygen-containing functional groups

Examples of terpenes are carotenoids and menthol

43
Q

Alkaloids

A

Nitrogen-containing molecules mostly synthesized from amino acids. Usually feeding deterrents and toxic to insects and other animals. Examples include Caffeine, Cocaine, Nicotine, Morphine

44
Q

Phenolics

A

Molecules containing phenol groups

45
Q

What are the 5 traditional plant hormones?

A

Auxin, abscisic acid, gibberellins, cytokinin, ethylene

46
Q

What does abscisic acid do?

A

Cause stomatal closure

47
Q

What does ethylene do?

A

Cause ripening in climacteric fruits, accelerate fruit abscission, promote female flower production in cucurbits

48
Q

What is plasmolysis?

A

When the cytoplasm loses water and pulls away from the rigid cell wall

49
Q

What is cation exchange capacity (CEC)?

A

A soil’s ability to retain and exchange cations

50
Q

What is the central dogma?

A

Information flow is from
DNA–>RNA–>protein

51
Q

What is a nucleotide made up of?

A

Phosphate group
Pentose sugar
Nitrogenous base

52
Q

What are the coding and noncoding regions of genes called?

A

Exons, which are transcribed to mRNA, and introns, which are spliced out of the mature mRNA molecule

53
Q

mRNA

A

Messenger RNA. Contains the codon (3 pase pair) information to build a protein

54
Q

rRNA

A

Ribosomal RNA. Assembles with ribosomal proteins to form the ribosome, which is where mRNA is read and translated to protein form

55
Q

tRNA

A

Transfer RNA. Carries amino acids to ribosomes to make proteins. Has an anticodon, which is the matching base pairs to the codon

An example of an anticodon for AUG is UAC because A matches with U, U matches with A, and G matches with C

56
Q

What is the process of turning DNA to RNA called?

A

Transcription

57
Q

What is the process of turning RNA to protein called?

A

Translation

58
Q

Crossing over

A

In meiosis, when two homologous chromosomes cross over at a chiasma, exchanging genetic information

59
Q

Linked genes

A

When two genes are on the same chromosome

60
Q

How does does crossing over affect linked genes?

A

Theoretically, one would expect linked genes to be segregate together because they are located on the same chromosome. But they don’t always do this.

For example, crossing a plant with linked genes coding for white flowers and large leaves with a plant with linked genes for purple flowers and small leaves, one would expect their offspring to only possess the phenotypes of their parents. In practice, this is not the case due to CROSSING OVER. Some of the offspring with have purple flowers with large leaves and some will have white flowers with small leaves.

61
Q

Why does crossing over happen in meiosis but not mitosis?

A

Because in meiosis, the chromosomes are positioned close together, whereas the homologous chromosomes in mitosis line up individually

62
Q

Lignin

A

Cell wall strengthening

63
Q
A

PLS 002A (22 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions