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Microbiology Lecture- Chapter 5 (Microbial Metabolism)

1.

The sum of all chemical reactions within a living organism is known as ______________.

Metabolism

2.

_______ refers to chemical reactions that result in the breakdown of more complex organic molecules into simpler substances. ________ reactions release energy.

catabolism
catabolic

3.

_________ refers to chemical reactions in which simpler substances are comined ro form more complex molecules. ___________ require more ____________.

Anabolism
anabolic

4.

The energy of________ is used to drive ____________.

catabolic reactions is used to drive anabolic reactions

5.

The energy for chemical reactions is stored in _____________.

ATP

6.

_______ are proteins produced by living cells.

Enzymes

7.

Enzymes function is to _____________________________________.

catalyze cheical reactionsby loering the activation energy

8.

Enzymes are generally __________proteins with characterstic ____________ shape.

globular
3-D shape

9.

Enzymes are efficient and can operate at relatively ________ temperatures and are subject to various cellular controls.

low

10.

Enzyme names usually end in _________.

-ase

11.

The 6 classes of enzymes are defined on the basis of the types of ________ they _____________.

reactions
catalyze

12.

Most enzymes are _____________ consisting of a _________ and a _________.

protein portion- (apoenzyme)
non-protein porttion- (co-factor)

13.

The cofactor can be a __________ (iron, cobalt, copper, magnesium, manganese, zinc and calcium) or a complex organic molecule known as ________________ (NAD+, NADP+, FMN, FAD, or coenzyme A).

metal ion
a coenzyme

14.

True or false. When an enzyme and substrate combine the substrate is transformed and the enzyme is recovered.

true

15.

Enzymes are characterized by ________________ which is characterized by their active sites.

specificity

16.

At ____________ temperatures enzymes undergo ____________ and lose their catalytic properties.

high
denaturation

17.

At __________ temperatures enzymes _________ rate _______________.

low
reaction rate
decreases

18.

The pHat which enzymatic activity is maximal is known as the __________ pH.

optimum

19.

Enzymatic activity increases as substrate concentration ___________ until the enzymes are _______________.

increases
saturated

20.

________ inhibitors compete with normal substrate for the ________ site of the enzyme.

Competitive
active

21.

_________ inhibitors act on other parts of the apoenzyme or on the cofactor and decrease the enzyme's ability to combine with normal substrate.

Non-competiitive

22.

__________ ________ occurs when the end product of a metabolic pathway inhibits an enzyme's activity near the start of the pathway.

Feedback inhibition

23.

________ are enzymatic RNA molecules that cut and splice RNA in eukaryotic cells.

Ribozymes

24.

_______ it the removal of one or more electrons from a substrate. Protons (H+) are removed with the electrons.

Oxidation

25.

Reduction of a substrate refers to its ______ of one or more ______________.

gain
electrons

26.

True or false. Each time a substance is oxidized another is simultaneously reduced.

True

27.

NAD+ is the reduced or oxidized form

oxidized

28.

NADH is the _______form.

reduced

29.

True or false. Glucose is a reduced molecule; energy is released during a cell's oxidation of glucose.

true

30.

Energy released during certain metabolic reactions can be trapped to form _____ from ___________ and (P)-phosphate.

ATP
ADP

31.

Adding a (P) to a molecule is called _______________.

Phosphorylation

32.

During substrate-level phosphorylation a ______________ (P) from an intermediate in catabolism is added to ADP.

high energy

33.

True or False. During oxidative phosphorylation energy is released as electrons are passed to a series of of electron acceptors (an electron transport chain) and finally to O2 or another inorganic compound,

true

34.

Photophosphorylation only happens in ___________ organisms.

photosynthetic organisms

35.

Catabolic reactions:

1.breakdown reactions
2. release energy (exergenic)
3. typically occur via hydrolysis

36.

Anabolic reactions:

Synthesis reactions-put together -build
require the input of energy (endergonic)
typically occur via dehydration synthesis

37.

dehydration synthesis (left to right)

a chemical reaction in which a molecule of water is released in the reaction of the monosaccharides glucose and fructose combine to form a molecule of the disaccharide sucrose.

38.

Hydrolysis (right to left)

in hydrolysis the sucrose molecule breaks down into the smaller molecules glucose and fructose. For the hydrolysis reaction to proceed, water must be added to the sucrose.

39.

What is the most usable form of energy?

ATP

40.

Catabolic ______ and _______ _________.

breakdown
and make ATP

41.

Anabolic ________ and ______ _______.

build and use ATP

42.

There are different types of energy

heat
light-plants
chemical energy

43.

ATP is _____________ energy.

chemical

44.

True or false. Heat is a useless energy it can't be reused.

true

45.

Organic molecules contain energy stored in their bonds. More specifically energy is associated with _______ that form those bonds.

electrons

46.

Most of a cell's energy is produced from the __________ of ________________.

oxidation of carbohydrates

47.

What is the most commonly used carbohydrate?

glucose

48.

The two major types of glucose catabolism are __________in which glucose is completely broken down and _________ is when it is partially broken down,

respiration
fermentation

49.

What is the most common pathway for the oxidation of glucose?

glycolysis

50.

What is the end product of glycolysis?

pyruvic acid

51.

Two ATP and two NADH are produced rom one ________ ________.

glucose molecule

52.

Cells extract energy and store it in ?

ATP

53.

Oxidation reactions involves the oxidation of a molecule. A molecule loses energy-containing electrons. Reduction reactions involves the reduction of a molecule. A molecule gains energy containing electrons. What is a good way to remember this ?

LEO goes GER
Loss of electrons is oxidation; gain of electrons is reduction
or
OIL RIG
oxidation is loss and Reduction is gain

54.

Adenosine triphosphate (ATP) does what?

1. stores chemical energy released by catabolic reactions
2. provides energy for anabolic reactions

55.

What is ATPs structure?

Adenosine unit (ribose and adenine) + 3 phosphate groups (3 like charges forced together =high energy bonds)

56.

What are the three mechanisms of ATP?

1. substrate level phosphorylation - transfer of a high energy phosphate from a phosphorylated compound to ADP (sharing phosphate with ADP)
2. Oxidative phosphorylation- cellular respiration
-ETC creates proton motive force
-H+ channeled through ATP synthase along the concentration gradient
-energy from proton motive force used to phosphorylate ADP
3. Photophosphorylation-Photosynthetic organisms
-occurs only in photosynthetic organisms
-process similar to phosphorylation

57.

During respiration _______ molecules are ________.

organic molecules
oxidized

58.

During cellular respiration energy is generated from the ________________.

Electron transport chain (ETC)

59.

In aerobic respiration what is the final electron acceptor?

O2 (oxygen)

60.

In anaerobic respiration what is the final electron acceptor?

any other inorganic molecule other than O2

61.

Decarboxylation of pyruvic acid produces one CO2 and one ________________ group.

acetyl

62.

True or false. Pyruvic acid cannot enter the Krebs's cycle.

true

63.

Collisions depend on?

molecular speed
molecular energy (only some will have enough)
molecular chemical configurations

64.

Rate of reaction increases when ______________.

Amount of heat is increased
-molecular movement increases
-frequency of collision increases
-number of molecules that are at or above the activation energy level increases
Other ways to increase reaction rate:
-increase the pressure
-increase the number of reactants

65.

True or false. Most enzymes are proteins.

true

66.

Enzymes function as ______________.

catalysts
-speed up chemical reactions
-lower the activation energy of the chemical reaction
-not used up in a chemical reaction
- specific to the reaction that it catalyzes
-act on specific substrate (s)

67.

Enzyme is like a puzzle. The pieces go in a specific way.

no answer just an analogy

68.

A substrate is_____________.

A molecule your enzymes works on to make another product.

69.

What site does the substrate bind to?

The active site-like a handshake a tightening fit

70.

Cofactor is another piece but it is not a ______________.

protein

71.

The cofactor and _________ make the whole piece that fits into the ________ site.

coenzyme
alosteric site

72.

What factors affect enzymes?

1. temperature (optimal 35-37*C)
2. pH (7 optimal)
3. substrate concentration- goes high and plateaus

73.

Enzyme inhibitors:

Competitive - competes directly for the active site
non-competitive- competes in directly for the alosteric site
-causes active site to change shape so the the correct substrate cant bind
(eg. DDT is an inhibitor)

74.

Stop signal of enzyme always binds to ___________ .

Enzyme 1

75.

Allosteric site does what?

causes active site to change shape halting substrate to fit

76.

The stop signal is the?

end product itself

77.

Cellular respiration is ______________________?

The process by which living organisms aerobically harvest energy from food

78.

Cellular respiration involves 3 major steps:

1. Glycolysis-breaking down of glucose
2.Kreb's cycle-removal of all energy
3.Electron Transport chain-

79.

Glycolysis is the _____________________.

Glucose breaking down -----> pyruvic acid
produces small amounts of ATP and NADH
occurs in cytoplasm

80.

In the Krebs's cycle two carbon acetyl groups are __________.Electrons are picked up by NAD+ and FAD for the electron transport chain.

oxidized

81.

From one molecule of glucose, oxidation produces __ molecules of NADH, two molecules of ________ and two molecules of ___________ .

6
FADH2
ATP

82.

Decarboxylation produces six molecules of ______ .

CO2

83.

Electrons are brought to the ETC by __________.

NADH

84.

The ETC consists of _______ carriers.

three

85.

Glycolysis means______________.

splitting of sugar

86.

One glucose molecule produces two ____ and two_____.

ATP and NADH

87.

The end product of glycolysis is ______________.

pyruvic acid

88.

True or false. Two molecules of ATP are invested.

true

89.

Step 1 of glycolysis:

glucose was phosphorylated and ATP was dephosphorylated.

90.

Step 3 of glycolysis:

Fructose-6 phosphate was phosphorylated while ATP was dephosphorylated.

91.

True or false pyruvic acid can't enter the Krebs's cycle.

true

92.

___________ is decarboxylated (carbon removed)and is oxidized by_________. Acetyl group is attached via a high energy bond to coenzyme A (CoA)

pyruvic acid
NAD

93.

Krebs's cycle steps:

acetyl enters the cycle
-CoA is reused to help another acetyl enter the Krebs's cycle
Acetyl is oxidized in a series of steps
CO2 is produced (all carbon that enters exists as CO2)
NADH and FADH are produced by redox reactions

94.

Krebs's cycle is the complete oxidation of _______.

acetyl
- pull all the energy out from acetyl ----> oxidation remove electrons.

95.

Oxygen is highly electronegative?

true

96.

Examples of final electron acceptors

Nitrate-E. coli and pseudomonas
Fe3+ geobacter

97.

Chemiosmosis is the generation of _____ using the ______.

ATP
ETC

98.

ETC is embedded in __________________.

plasma membrane

99.

Most of the cell's ATP is produced at this stage __________ .

chemiosmosis

100.

H+ diffuse across the membrane through ______ channels containing an enzyme ______________.

protein
ATP synthase

101.

know this summary

no data
102.

Fermentation is the metabolic process used to extract energy from a sugar or other _______ molecule.

organic

103.

True or false. Fermentation does not require the Krebs's cycle or ETC

true

104.

Does fermentation require oxygen?

no

105.

In fermentation the final electron acceptor is _____________.

organic

106.

It will either produce _______ or ______________.

alcohol
acid

107.

Does fermentation yield any ATP?

yes but in small amounts only during glycolysis

108.

Two types of fermentation:

1. lactic acid fermentation:
-pyruvic acid-----> lactic acid (streptococcus and lactobacillus are lactic acid bacteria)
homoplactic- can only produce lactic acid
2. alcohol fermentation:
-reduced
-heterolactic (variety of products due to fermentation)