Biochem Module 8 Flashcards
1
Q
True or False
Metabolism never stops
A
True
2
Q
- totality of all the chemical reactions that take place in a living cell by which the body breaks down and builds up molecules.
- elaborate road map of the chemical reactions in that cell.
A
Metabolism
3
Q
The fluid portion of the cell which is involved in anaerobic metabolism
A
Cytosol
4
Q
Plays a key role in aerobic energy production
A
Mitochondria
5
Q
- any metabolic process whereby cells break down complex substances into simpler, smaller ones, more basic molecules
- Releases energy
A
Catabolic reactions
6
Q
- any metabolic process whereby cells convert simple substances into more complex ones.
- consumes/requires energy.
A
Anabolic Reactions
7
Q
Anabolic reactions is critical for ____, ____, ____, and ____ of body tissue
A
growth, repair, maintenance, synthesis
8
Q
How Does the Body Fuel Metabolism?
A
- disassembles macronutrients
- builds new compounds
- transforms compounds to ATP
9
Q
Two Discrete Groups of Pathways
A
- Energy conversion pathways
- Metabolite synthesis and degredation pathways
10
Q
What are the conversion pathways under Energy Conversion Pathways
A
- glycolysis
- citrate cycle/TCA cycle
- oxidative phosphorylation or electron transport chain
- photosynthesis and carbon fixation
11
Q
What are the conversion pathways under Metabolite Degradation Pathways
A
- fatty acid degredation: beta -oxidation
- gluconeogenesis
12
Q
What is the sequence of events in digestion and absorption of carbohydrates
A
mouth > stomach > small intestine > large intestine
13
Q
The enzyme salivary amylase breaks down starch into shorter polysaccharides
A
mouth
14
Q
salivary amylase is inactivated and no further carbohydrate digestion occurs
A
stomach
15
Q
- majority of starch digestion and breakdown of disaccharides occur here.
- the enzyme pancreatic amylase breaks down starch into monosaccharides, disaccharides, and oligosaccharides
A
small intestine
16
Q
the digestion of carbohydrates is completed by?
A
enzymes attached to the border of the small intestinal villi
17
Q
- fiber and other indigestible carbohydrates are partially broken down by bacteria to form short chain fatty acids and gas
- the remaining fiber is excreted in the feces
A
large intestine
18
Q
Conversion of glucose to pyruvate that involves 10 steps of enzymatic reactions.
A
glycolysis
19
Q
Where does glycolysis occur
A
cytosol
20
Q
True or False
Glycolysis is an aerobic reaction
A
False
Glycolysis is an anaerobic reaction
21
Q
glycolysis is reversible through?
A
gluconeogenesis
22
Q
- Process by which carbohydrates provide energy to the cell
- Backbone of metabolism
A
glycolysis
23
Q
One glucose molecule in glyscolysis yields?
A
- 2 pyruvate
- 2 ATP
- 2 energized coenzymes
- 2 hydrogen ions
- 2 water molecules
24
Q
In the absence of oxygen, pyruvate accepts hydrogens that are released during glycolysis resulting in the conversion of lactate, and NAD+ is “free” to work again as a coenzyme in the first steps of glycolysis.
A
cori cycle
25
In the presence of Oxygen, pyruvate is transported into the ____ and is converted into ____
mitochondira ; acetyl CoA
26
synthesis of glucose or carbohydrates from non-carbohydrate precursor molecules.
gluconeogenesis
27
* Break down of glycogen to glucose
* Inhibited by insulin
glycogenolysis
28
what is the key enzyme in glycogenolysis
Glycogen phosphorylase
29
glycogenolysis is stimulated by?
fasting, physical exercise (between meals), glucagon, epinephrine
30
* Synthesis of glycogen from glucose
* Inhibited by glucagon, epinephrine
glycogenesis
31
what is the key enzyme in glycogenesis
Glycogen synthase
32
glycogenesis is stimulated by?
increased blood sugar level (well fed state), insulin
33
# True or False
Glycogen phosphorylase is **phosphorylated** in its active form while Glycogen synthase is **dephosphorylated** in its active form
True
34
Where Do the Macronutrients Come Together?
Acetyl CoA
35
also known as the "gateway" molecule for aerobic metabolism
acetyl CoA
36
* Gathers electrons from the carbons in the energy nutrients
* Transfers stored energy to two coenzyme hydrogen ion carriers to be released in the electron transport chain
The Tricarboxylic Acid (TCA) Cycle
37
primary function of TCA cycle
oxidize acetyl-CoA
38
The TCA cycle is considered the "hub' of cellular metabolism because?
1. central to aerobic metabolism and ATP production by generating the bulk of NADH and FADH2
2. links the oxidation of various metabolic fuels to ATP synthesis
3. provides metabolites for numerous biosynthetic pathways
39
TCA cycle produces?
* 2 carbons
* 8 hydrogen atoms
* 3 NADH & 1FADH₂
* small amount of energy as GTP
40
____ is produced in the liver, stored in the gallbladder, and released into the small intestine to aid in the digestion and absorption of lipids
bile
41
the enzyme ____ is produced by the pancreas and released into the small intestine to break down triglycerides into monoglycerides, fatty acids, and glycerol
pancreatic lipase
42
in the small intestine, the products from fat digestion and bile acids form a ____
micelle
43
what is the purpose of the micelle
moves towards the microvilli to allow the lipids to diffuse into the mucosal cells
44
lipid transport particles are also called?
chylomicrons
45
# True or False
Dietary fat (triglycerides) yields six times more energy
True
46
hydrolyzed during lipolysis
triglycerides
47
triglycerides are catalyzed by an enzyme in the adipose tissues by a) ____ and b) ____
* **Glucagon** during times of fasting or starvation
* **Epinephrine** or cortisol when under stress
48
what are the products of lipolysis
glycerol and 3 fatty acids
49
produces little energy
glycerol
50
can be transformed to
glucose
glucogenic
51
can be transformed into ketone bodies
ketogenic
52
Ketone bodies are the backup fuel for ____ and ____ when glucose is limited
brain and nerve function
53
ketone bodies are converted into acetyl-CoA via?
β-Oxidation
54
Before Oxidation, fatty acids must be activated and transported to the ____ via ____
mitochondrion ; carnitine
55
# True or False
In β-Oxidation of Fats, activation begins in the **nucleus**
False
| Activation begins in the **cytoplasm**
56
* conversion of fatty acids to acetyl-coA
* involves 4 steps of enzymatic reactions
* occurs in **mitochondria**
β-Oxidation of Fatty Acids
57
what are the products in β-Oxidation of Fats (for palmitic acid)
* 8 acetyl-CoA
* 7 hydrogens
* 7 FADH2
* 7 NADH
58
how much atp is produced in β-Oxidation
106 ATP
59
in the stomach, the chemical digestion of protein begins from ____ and the enzyme ____
hydrochloric acid ; pepsin
60
Ketogenic amino acids
* leucine
* lysine
61
Both ketogenic and glucogenic amino acids
* Isoleucine
* Tryptophan
* Phenylalanine
* Tyrosine
62
Glucogenic amino acids
* Alanine
* Valine
* Methionine
* Histidine
* Glutamic acid
* Glutamine
* Arginine
* Aspartic acid
* Serine
* Proline
* Cysteine
* Glycine
63
what is the most abundant glucogenic acid
glutamine
64
glucogenic acids are converted to ____ and then transformed into ____ through ____
pyruvate, glucose, glucogenesis
65
ketogenic amino acids are converted to ____ which can either be transformed into ____ and stored as a triglyceride or ____
acetyl-CoA, fatty acids, enter the TCA cycle
66
# True or False
Some amino acids can enter TCA cycle directly
True
67
Major source of blood glucose when the diet is lacking in carbohydrate
glucogenic amino acids
68
once glucogenic amino acids are deaminated, they can be transformed into:
* pyruvate
* acetyl-CoA
* TCA cycle compounds
69
in amino acid metabolism, 20 amino acids are converted to:
1. pyruvate
2. acetyl-CoA
3. acetoacetate
4. α-ketoglutarate
5. succynyl-CoA
6. oxalacetate
7. fumarate
70
A process wherein nonessential amino acids are produced in the TCA Cycle.
Transamination
71
There are ____ glucogenic amino acids
14
| There are 14 amino acids that are **purely** glucogenic
72
Electron Transport Chain is also known as?
Oxidative Phosphorylation
73
* Final stage of metabolism when electrons are transferred from one complex to another, resulting in the formation of ATP and water
* Generates 90% of the ATP used by the body for energy, growth, and maintenance
Electron Transport Chain
74
ETC takes place in?
inner mitochondrial membrane of the cell (matrix)
75
* Protein complexes that transfer the electrons through the electron transport chain
* Contain B vitamin riboflavin
Flavoproteins
76
also known as Coenzyme Q, an electron carrier
Ubiquinone
77
# True or False
Iron deficiency can slow down ETC
True
78
* Protein complexes that move electrons down the electron transport chain
* Contain iron and copper
Cytochrome C
79
A process by which autotrophic organisms convert solar energy into glucose and O2
Photosynthesis
80
where does photosynthesis occur
chloroplast
81
what are the two phases of photosynthesis
1. light dependent reaction
2. light independent reaction (calvin cycle)
82
produces Oxygen, ATP and NADPH
Light Dependent Reaction
83
Uses ATP and NADPH to make glucose
Light Independent Reaction (Calvin Cycle)
84
Light Dependent Reaction occurs at?
thylakoid membrane
85
A photon of light strikes an arrangement of chlorophyll called ____, causing the excitement of electrons and the splitting of water
photosystem II
86
The H+ ions produced in Photosystem II are used to generate ATP through
ETC and chemiosmosis
87
The electron is passed to photosystem I, where it is reenergized by another photon and used to generate an electron carrier called?
NADPH
88
The chlorophyll found in photosystem II and I is referred to as
P680 & P700
| They respond best to light at wavelengths 680nm & 700nm (red)
89
During the Calvin cycle, 6 molecules of carbon dioxide are used to synthesize 2 molecules of a 3-carbon sugar called?
glyceraldehyde-3- phosphate or G3P
90
The enzyme that attaches the molecule of carbon dioxide to the 5-carbon molecule RuBP is called
rubisco
91
Rubisco is sometimes referred to as?
bridge or gateway to life
92
What Happens if You Eat Too Much or Too Little
Metabolism adjusts
93
When eating plenty, ____ are favored by metabolism
anabolic reactions
94
Metabolism shifts during fasting to ____
catabolic reactions
95
# True or False
Ketogenesis peaks **five days** into fasting or limited carbohydrate intake
False
| Ketogenesis peaks **three days** into fasting
96
* can result from a buildup of excess ketone bodies in the blood
* often seen in type 1 diabetics
Ketoacidosis
97
# True or False
Alcohol is also metabolized in the brain
True
