Brainscape's Knowledge GenomeTM

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


See full index

Kris 307 > 1. Biochemistry of Life (Part I) > Flashcards

1. Biochemistry of Life (Part I) Flashcards

1
Q

What nutrients are necessary during cell division?

A
  • Energy
  • Proteins to create new structures and motors
  • Lipids to create cell membranes
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Define nutrigenetics.

A

Genes control the metabolism of nutrients

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

Define nutrigenomics.

A

Nutrients influence the expression of genes

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

Explain what happens on a molecular level to the lac operon when there is a lack of lactose.

A
  • lacI encodes the repressor protein
  • The repressor protein binds to the lac operator, present in the promoter region of the lac operon
  • This ultimately shuts down the transcription of the operon
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Explain what happens on a molecular level to the lac operon when there is lactose.

A
  • Lactose binds to the repressor protein, which causes a conformation change
  • The changed repressor is unable to bind to the lac operator region
  • RNA polymerase can see the promoter, and make RNA for the lacZ, lacY, and lacA regions (genes known for their role in lactose metabolism)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What are the three genes that are known to be involved in the metabolism of lactose?

A
  • B-Galactosidase
  • Permease
  • Transacetylase
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is a responsive gene?

A
  • Either be induced or repressed by a dietary constituent

- If it does not do either, it is not a responsive gene

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

What do secondary mediators have an impact on in nutrient-gene interactions? What are they affected by?

A
  • They have an impact on their own responsive genes

- They are indirectly affected by dietary constituents

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

What are the five ways dietary constituents can interact with genes, either directly or indirectly?

A
  • Responsive genes (direct)
  • Physiological modulation (indirect)
  • Regulation of transcription
  • Regulation of translation
  • Modification of proteins
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Explain how amino acids and fatty acids regulate gene expression indirectly.

A
  • Interact with a protein embedded on a cell membrane, which will initiate a signal transduction pathway (e.g. phosphorylation-chain)
  • When the signal reaches the nucleus, the protein interacts with a promoter region of a gene to induce or repress RNA transcription
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Concerted Regulation of Protein and Lipid Biosynthesis occurs by which pathway?

A

The Akt/mTORC1 pathway

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

What are the four proteins involved in the Akt/mTORC1 pathway?

A
  • AMPK
  • Akt
  • mTORC1
  • SREBP
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

AMPK and Akt are components of a signalling pathway. What are their functions?

A
  • AMPK: responds to cellular energy status

- Akt: responds to growth factors, including insulin

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

What is the role of mTORC1?

A
  • Integratesthe information related to the kind:
  • Nutrients available
  • Cellular energy status,
  • Growth factors interacting with the cell receptor
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What does the Akt/mTORC1 pathway affect?

A

Regulates protein and lipid biosynthesis

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

True or False: if you increase your mass of cells, you increase your lipid content. Why or why not?

A
  • True

- Due to the Akt/mTORC1 pathway, which regulates cell growth through protein AND lipid biosynthesis

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

Why is glucose uptake necessary for the Akt/mTORC1 pathway?

A

Since the production of protein and lipid biosynthesis is an energetically expensive process, which requires the production of ATP through glycolysis and the TCA cycle

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

What is SREBP responsive to?

A

To the status of cholesterol in the environment

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

Explain what happens to SREBP when you have low sterol concentrations.

A
  • SREBP, interacting with SCAP and COPII, migrates from the ER towards the Golgi
  • At the Golgi, the SREBP protein is processed by specific proteases of the Golgi
  • The proteases liberate a portion of SREBP, which migrates to the nucleus and binds to the Sterol Response Element (SRE)
  • SRE stimulates the target genes involved in cholesterol and fatty acid biosynthesis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Explain what happens to SREBP when you have high sterol concentrations.

A
  • SREBP remains bound to SCAP, which is bound by INSIG, and remains in the ER
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Give examples of abundant elements.

A

Carbon, hydrogen, nitrogen, oxygen, phosphorus

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

Give examples of trace elements.

A

Calcium, chlorine, cobalt, copper, iodine, iron, manganese, magnesium, potassium, sodium, sulphur, selenium, zinc

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

What raw materials are necessary for life?

A
  • Carbon source
  • Nitrogen source (protein and DNA)
  • Water
  • Oxygen
  • Salts
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Which terminal of an amino acid corresponds to the 5’-end of the gene that encodes it? What about the 3’-end?

A
  • N-terminal (+) = 5’

- C-terminal (-) = 3’

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

What is hydrolyzed protein used for?

A
  • Common in some large scale food manufacturing

- Texturizer, flavour enhancer

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

Explain how hydrolyzed proteins may be hypoallergenic.

A

If you break up a protein, our immune system might not recognize its different three-dimensional structure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What is the function of glutamic acid as a neurotransmitter?

A

Involved in long-term potentiation (learning and memory)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

What symptoms has MSG been suggested to cause?

A
  • Headaches
  • Numbness
  • Tingling sensations
  • Obesity
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

What are the three kinds of MSG manufacturing? Are they L or D amino acids?

A
  • Hydrolysis of proteins (L-amino acids)
  • Chemical synthesis (DL-glutamate; synthetic)
  • Fermentation (L-glutamate)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

How does L-glutamate made by chemical synthesis differ from L-glutamate made by fermentation?

A

They are the same despite chemical synthesis being synthetic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Which foods contain MSG?

A
  • Anything that contains “protein hydrolysate” (prepared foods, protein supplements)
  • Fermented food products (soy sauce, Worcestershire sauce, vegemite)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

Define homeostasis.

A
  • Homeostasis occurs when the rate of input is equal to the rate of output
  • Disease states occur when there is dysregulation in homeostasis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

What is gout? What is the cause?

A
  • A painful genetically-predisposed disorder characterized by joint inflammation.
  • Caused by high uric acid concentration in the body due to high production or inefficient disposal of uric acid.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

Is RNA or DNA easier to degrade?

A

RNA is easier to degrade; DNA is sequestered in the nucleus anyways

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

Explain how high uric acid concentration leads to the irritation and inflammation of joints.

A

Leads to the formation of uric crystals

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

Why is gout aggravated by an animal-based diet?

A
  • They contain a higher proportion of purines (nucleic acids) than plant-based diets
  • By unit-mass, there is more DNA compared to plant-based diets
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

What is uric acid synthesized from in humans?

A

Adenine and guanine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

How do lipids differ from other macromolecules?

A
  • They are not defined as polymers, but detain a functional classification
  • Lipids are all hydrophobic molecules (fatty acids, cholesterol) and do not have a common subunit
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

What are the two sections of fatty acids?

A
  • Carboxyl-end (hydrophilic)

- Methyl-end (hydrophobic)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

Describe the varying lengths of fatty acid chains.

A
  • Short-chain (2-6 carbons)
  • Medium-chain (8-10 carbons)
  • Long-chain (12-20 carbons)
  • Very long-chain (>20 carbons)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

How does palmitic acid compare to stearic acid?

A

Palmitic (16:0) is bad, stearic acid (18:0) is better

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

What are the three different uses of fatty acids?

A
  • Energy source
  • Structural component
  • Substrate for the synthesis of signalling molecules
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

How are fatty acids stored?

A

In triacylglycerols

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

Is cholesterol a fat?

A

No, because solid fats and liquid oils are made of triacylglycerols
It’s a lipid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

Give examples of interactions occurring within the lipid bilayer.

A
  • Integral membrane proteins
  • Peripheral membrane proteins
  • Glycoproteins
  • Carbohydrate side chains of glycoproteins
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

What is the role of phospholipases?

A
  • Release fatty acids

- Leaves you with a lysophospholipid (missing a fatty acid)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

Give examples of acquired metabolic syndromes.

A
  • Obesity
  • Atherosclerosis
  • Fatty liver disease
  • Gallstones
  • Hypertension
  • IBD
  • Diabetes
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q

What does the sentence “food components are bioactive” mean?

A
  • Nutrients are not solely needed to build muscle, bone and energy
  • Nutrients are a part of what makes cells work, regulate their activity, and are the components of what they are made of
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
49
Q

Do plant-based foods have cholesterol?

A

No, they have sterols

50
Q

What is particular about plant-based sterols?

A

They are poorly absorbed because transporters are configured to solely recognize cholesterol

51
Q

What is needed to synthesize cholesterol?

A
  • HMG-CoA reductase

- The quantity of HMG-CoA reductase is a rate-limiting enzyme, which dictates the efficiency of the pathway

52
Q

What is the function of statins?

A

Inhibit HMG-CoA reductase, and blocks cholesterol synthesis

53
Q

________ is a lipid that is a precursor of highly bioactive molecules.

A

Cholesterol

54
Q

Can cholesterol be oxidized to produce energy?

A

No, ATP spent synthesizing this molecule cannot be recovered

55
Q

Cholesterol is a substrate for the synthesis of what?

A
  • Steroid hormones
  • Vitamin D
  • Bile acids
56
Q

What is cholesterol required for?

A
  • The control of membrane fluidity
  • Required for proteins to move and undergo conformational changes, respond to temperature changes, and allow substances to pass through
57
Q

Cholesterol is a highly bioactive molecule that needs to be regulated to be kept within an optimal range. What homeostatic mechanism occurs when there is too much cholesterol?

A
  • Cholesteryl esters (inactive) are synthesized and stored in an oil droplet
  • Choleseteryl esters can’t be used to make steroid hormones or bile acids
  • They need to be converted to cholesterol to become bioactive again
58
Q

Define a nutrient.

A

A nutrient is either a chemical element or compound that is used in the metabolic processes of, or forms an integral component of the physiology of an organism

59
Q

What are macronutrients?

A
  • Needed in large quantities
  • Carbohydrates, proteins, fat
  • Nucleic acids are not a source of energy
60
Q

What are micronutrients?

A
  • Small quantities

- Vitamins and minerals

61
Q

What is the criteria for nutrient essentiality?

A

That absence of the nutrient from the diet results in characteristic signs of a deficiency disease and these signs are prevented only by the nutrient itself, or a specific precursor of it

62
Q

What are the essential amino acids?

A
  • Phenylalanine
  • Valine
  • Tryptophan
  • Threonine
  • Isoleucine
  • Methionine
  • Histidine
  • Arginine (in children and special cases; preterm infants are unable to synthesize or create Arginine internally)
  • Lysine
  • Leucine
63
Q

What are the essential fatty acids?

A
  • Fatty acids with double bonds located at positions 8 or less (counting from the methyl end)
  • Linoleic acid
  • Linolenic acid
64
Q

What are the essential fat-soluble vitamins?

A
  • A
  • D
  • E
  • K
65
Q

What are the essential water-soluble vitamins?

A
  • B1, B2, B3, B5, B6, B7, B9, B12
  • C
  • Choline
66
Q

What is vitamin A?

A

Retinol

67
Q

What is vitamin D?

A

Ergocalciferol, cholecalciferol

68
Q

What is vitamin E?

A

Tocopherol

69
Q

What is vitamin K?

A

Naphthoquinoids

70
Q

What is vitamin B1?

A

Thiamine

71
Q

What is vitamin B2?

A

Riboflavin

72
Q

What is vitamin B3?

A

Niacin

73
Q

What is vitamin B6?

A

Pyridoxine

74
Q

What is vitamin B5?

A

Pantothenic acid

75
Q

What is vitamin B9?

A

Folic acid

76
Q

What is vitamin B12?

A

Cobalamin

77
Q

What is vitamin B7?

A

Biotin

78
Q

What are the four functions of choline?

A
  • Susbtrate for phosphatidylcholine biosynthesis
  • Ensures the structural integrity and signaling functions of cell membranes
  • Source of methyl groups
  • Used to make a variety of very important metabolites (e.g. acetylcholine, platelet-activating factor, betaine)
79
Q

What is the mechanism that spares choline when it is deficient?

A

The body will recover and reabsorb all the choline it secretes in the bile

80
Q

Describe the de novo synthesis of choline.

A
  • Three successive methylations (recovers methyl groups) of the phosphatidylethanolamine headgroup generates phosphatidylcholine
  • Choline can be released from phosphatidylcholine
81
Q

What are the essential macrominerals? What is their function?

A
  • Calcium
  • Chloride ion
  • Phosphorus
  • Important in forming active enzymes needed to support metabolism
82
Q

What are phytochemicals?

A
  • A broad and diverse group of plant-derived compounds

- Compound that you can’t find anywhere else other than plants

83
Q

Which phytochemicals are thought to have beneficial effects on health? Are all phytochemicals good?

A
  • Flavonoids

- No, some are very toxic

84
Q

Define malnutrition.

A
  • Refers to improper to insufficient diet

- Nutrient deficiency and nutrient excess

85
Q

What are essential fatty acids substrates for?

A

A class of molecules called eicosanoids

86
Q

Give examples of eicosanoids.

A
  • Prostaglandins
  • Leukotrienes
  • Thromboxanes
87
Q

What are the functions of essential fatty acids?

A
  • Immune function
  • Inflammatory response
  • Blood clotting
  • Vasodilation
  • Kidney function
  • Cognitive function
88
Q

What are the consequences of essential fatty acid deficiency?

A
  • Growth retardation
  • Sparse hair growth, dry skin and scaling (excema)
  • General weakness
  • Depression
  • Poor wound healing, increased susceptibility to infection
  • Edema
  • Vision problems
  • Neurological problems (particularly in severe cases).
89
Q

What are the consequences of essential fatty acid excess?

A
  • Currently, does not appear to cause severe problems.

- May cause excessive bleeding (slow blood clotting)

90
Q

What is the essential function of vitamin A?

A

Maintenance of epithelial cells

91
Q

Vitamin A and other retinoids are ________. What does this mean?

A
  • Teratogenic

- Disturbs the development of the embryo or fetus

92
Q

Vitamin A is the ligand for which receptors? What happens if you supply too much vitamin A?

A
  • Retinoic acid receptor (RAR) and retinoid x receptor (RXR)

- If you supply too much vitamin A, you inappropriately induce the expression of genes, which may cause damage

93
Q

Where is vitamin A found? How does overdose usually occur?

A
  • Coloured fruits and vegetables
  • Difficult to overdose on fruits and veggies
  • Overdose usually occurs with supplements and drugs (e.g. Acutane)
94
Q

How does vitamin A deficiency lead to xerosis? What is xerosis?

A
  • Abnormal dryness

- Causes mucus-secreting cells to be replaced by keratin producing cells

95
Q

What is the consequence of vitamin A deficiency?

A
  • Primarily affects eye function
  • Eye blindness
  • Eye xerosis causes ulcerations and leads to blindness
96
Q

People with diseases involving the absorption of lipids are at risk for which deficiency?

A

Vitamin A

97
Q

What are the consequences of vitamin A excess?

A
  • Birth defects
  • Reduced bone mineral density
  • Weight loss, headache, vision problems, dry itchy skin, hair loss, anemia, teeth discolouration, enlarged liver and spleen
98
Q

Is iron a macromineral or a micromineral?

A
  • Transition metal

- Micromineral

99
Q

What is iron’s main function?

A
  • Used by a prosthetic group by many biologically important proteins (ex: heme groups of hemoglobin, myoglobin)
  • Generally found in enzymes involved in carrying or metabolizing oxygen
100
Q

How much iron does the average person contain? Where is it largely found

A
  • 3-4 grams of iron

- 60% in the blood

101
Q

What is the average intake of iron? What is the average absorption?

A
  • 15 mg

- 2 mg

102
Q

What % of the world is deficient in iron?

A

80

103
Q

What individuals are at risk for iron deficiency anemia?

A
  • Alcoholics

- Patients with infectious, inflammatory, or neoplastic diseases

104
Q

What are the symptoms of iron deficiency anemia?

A
  • Pale skin
  • Tired and weakness
  • Difficulty maintaining body temperature
  • Shortness of breath
  • Inflamed tongue
  • Diminished cognitive function
  • Decreased immune function
105
Q

How does iron loss occur?

A
  • Shedding of epithelial surfaces
  • Through occult blood loss in the intestine
  • Menstruation
  • Lactation
106
Q

What is the cause of secondary hemochromatosis?

A
  • Excessive alcohol consumption

- Excessive use of dietary iron supplements

107
Q

What other disorders can iron excess lead to?

A
  • Arthritis
  • Liver disease leading to liver failure
  • Damage to the pancreas causing diabetes
  • Cardiac function abnormalities
  • Impotence
  • Abnormal skin pigmentation (making it look grey or bronze)
  • Thyroid deficiency
  • Damage to the adrenal glands
108
Q

Is iodine a macromineral or a micromineral?

A
  • Halogen

- Micromineral

109
Q

What are the major functions of iodine?

A
  • Necessary for normal thyroid function

- Essential substrate for the synthesis of thyroid hormones

110
Q

What are the functions of thyroid hormones?

A
  • Control many aspects of energy (carbohydrate and fat) metabolism
  • Ligands of TR receptor (transcription factor belonging to the nuclear receptor superfamily of transcription factors)
111
Q

What are sources of iodine?

A
  • Seafood (cod, sea bass, haddock, perch)
  • Kelp
  • Dairy products
  • Iodized table salt
112
Q

What are the consequences of iodine deficiency?

A
  • Increased fetal and infant mortality
  • Neurological defects
  • Mental retardation (cretinism)
  • Decreased reproductive fitness
  • Hypothyroidism
  • Goiter (hypertrophy of the thyroid gland)
113
Q

What are secondary thyroid related disorders?

A
  • Anemia
  • Arthritis
  • Eye enlargement and inflammation
  • Hair loss and premature graying of hair
  • Inflammatory bowel diseases
  • Depression
114
Q

What is the cause of goiter?

A
  • Iodine deficiency; impaired by thyroid hormone synthesis

- Also caused by excessive iodine, which results in the inhibition of thyroid hormone production

115
Q

Does an excess of iodine develop more or less problems than iodine deficiency?

A

Excess iodine develops less problems than iodine deficiency

116
Q

What are the consequences of an excess of iodine?

A
  • Skin ulceration (“kelp acne”, high incidence in Japan where kelp is consumed in large quantities)
  • Impairs thyroid hormone production and causes goiter in response to decreased thyroid hormone concentration
117
Q

What is the lacZ region associated with?

A

B-galactosidase

118
Q

What is the lacY region associated with?

A

Permease

119
Q

What is the lacA region associated with?

A

Transacetylase

120
Q

What does the inhibitor protein of the lac operon bind to in order to shut down transcription?

A

lacO

121
Q

How do statins function?

A
  • By competitively inhibiting to HMG-CoA reductase

- Competitive binding to the active site of HMG-CoA reductase prevents HMG-CoA from binding to produce mevalonate

122
Q

What binds to HMG-CoA reductase? What is produced?

A
  • HMG-CoA binds

- Mevalonate is produced

Kris 307 (19 decks)

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