BIOM1051 > module 2 > Flashcards

module 2 Flashcards

biochemistry (110 cards)

Study These Flashcards
1
Q

What are the four types of large biological molecules that all living things rely on?

A
  • Carbohydrates
  • Lipids
  • Proteins
  • Nucleic acids

These molecules are essential for various biological functions and are built from smaller molecules.

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

Define a polymer.

A

A long molecule consisting of many similar building blocks

Polymers are made from smaller units called monomers.

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

What is a monomer?

A

Small building-block molecules that make up polymers

Monomers join together to form larger macromolecules.

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

What is a condensation reaction?

A

A reaction when two monomers bond together and lose a water molecule

This process is also known as a dehydration reaction.

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

What is hydrolysis?

A

A reaction that disassembles polymers to monomers

Hydrolysis is the reverse of the dehydration reaction.

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

What role do enzymes play in biological reactions?

A

They speed up both condensation and hydrolysis reactions

Enzymes are typically protein macromolecules.

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

What are the simplest carbohydrates called?

A

Monosaccharides

These are single sugars, with glucose being the most common example.

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

What is a disaccharide?

A

A carbohydrate formed when two monosaccharides are joined by a dehydration reaction

The covalent bond formed is called a glycosidic linkage.

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

What are polysaccharides?

A

Polymers composed of many sugar building blocks

They serve storage and structural roles in organisms.

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

What is starch?

A

A storage polysaccharide of plants, consisting entirely of glucose monomers

Plants store surplus starch as granules within chloroplasts.

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

What is the role of cellulose in plants?

A

An important structural component of the cell wall

Cellulose is the most abundant organic polymer on Earth.

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

What is glycogen?

A

A storage polysaccharide in animals

Humans and other vertebrates store glycogen mainly in liver and muscle cells.

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

What type of bond is formed in cellulose?

A

β(1→4) glycosidic bonds

This contrasts with the α(1→4) glycosidic bonds present in starch.

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

What is the most common monosaccharide?

A

Glucose (C6H12O6)

It is a primary energy source for cells.

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

True or false: Monosaccharides can vary in length of carbon skeleton.

A

TRUE

They can range from 3 to 6 carbons in length.

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

What is the significance of glycosidic linkages?

A

They connect monosaccharides to form disaccharides and polysaccharides

The structure and function of polysaccharides depend on the positions of these linkages.

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

What is the function of carbohydrates?

A
  • Serve as fuel
  • Serve as building material

Carbohydrates include sugars and polymers of sugars.

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

What is the octet rule?

A

A chemical rule that reflects the tendency of atoms to prefer having eight electrons in their valence shell

This rule is often applied in drawing molecular structures.

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

What is electronegativity?

A

The tendency of an atom to attract electrons towards itself

It plays a crucial role in determining the polarity of bonds.

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

Is CH3COOH soluble in water? Explain why or why not.

A

Yes, because it is polar and can form hydrogen bonds with water

CH3COOH is acetic acid, which is soluble in water.

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

Is CH3COOH an acid or a base?

A

An acid

It donates protons (H+) in solution.

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

Write down the equilibrium reaction for CH3COOH when it combines with water.

A

CH3COOH + H2O ⇌ CH3COO- + H3O+

This reaction illustrates the acid-base chemistry of acetic acid.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q
A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

List the functions of proteins.

A
  • Structural support (collagen)
  • Storage (casein)
  • Transport (hemoglobin)
  • Hormonal regulation (insulin)
  • Movement (actin/myosin)
  • Defence (immunoglobulin)
  • Enzymes (catalysts)

Each function highlights the diverse roles proteins play in biological systems.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
What are **enzymes**?
Proteins that act as catalysts to speed up chemical reactions ## Footnote Enzymes can perform their functions repeatedly, essential for life processes.
26
True or false: **Enzymes** can only catalyze reactions once.
FALSE ## Footnote Enzymes can catalyze reactions repeatedly.
27
What is the **turnover number** (k_cat)?
Indicates how fast a single enzyme molecule can convert substrate to product ## Footnote A larger k_cat value indicates a more efficient enzyme.
28
What does **K_m** indicate?
The affinity of the substrate for the enzyme ## Footnote A lower K_m value means a higher likelihood of substrate-enzyme engagement.
29
What is the **Michaelis constant** (K_m)?
The substrate concentration at which V_0 is half maximal ## Footnote It helps in understanding enzyme kinetics.
30
What are **amino acids**?
Organic molecules with carboxyl and amino groups ## Footnote Amino acids differ in properties due to differing side chains (R groups).
31
What is a **polypeptide**?
A polymer built from a set of 20 amino acids ## Footnote A protein consists of one or more polypeptides.
32
What does **pK_a** represent?
The equilibrium constant for an acid-base equilibrium ## Footnote It is used to determine the ionization state at a certain pH.
33
Fill in the blank: For the conjugate base to dominate, **pH** > _______.
pK_a ## Footnote This indicates that the concentration of the base is greater than that of the acid.
34
What is the charge state of amino acids at **pH = 7**?
Zwitterionic form ## Footnote At physiological pH, amino acids typically exist in this form.
35
What type of amino acids are most **α-amino acids**?
Chiral ## Footnote The central α-carbon has four different substituents.
36
What links amino acids together?
Peptide bonds ## Footnote These bonds form during protein synthesis.
37
What are the properties of **side chains** in amino acids?
* Hydrophobic (non-polar) * Hydrophilic (polar) * Charged * Aromatic ## Footnote These properties influence protein structure and function.
38
Explain the **catalytic cycle** of enzymes.
The process by which enzymes convert substrates into products ## Footnote Understanding this cycle is crucial for studying enzyme kinetics.
39
What is the **primary structure** of a protein?
The amino acid sequence ## Footnote Proteins are drawn from the amino end to the carboxy terminal end, with amino acids numbered starting from the amino end.
40
Name the two common **secondary structures** of proteins.
* α helix * β sheet ## Footnote These structures are stabilized by hydrogen bonds between nearby residues or adjacent segments.
41
What type of interactions contribute to the **tertiary structure** of a protein?
* Non-covalent interactions * Hydrogen bonds * Ionic bonds * Hydrophobic/van der Waals interactions * Disulfide bridges ## Footnote The tertiary structure is the overall three-dimensional shape of a polypeptide.
42
What is the **quaternary structure** of a protein?
The assembly of polypeptide chains ## Footnote Chains can be identical or different in sequence, as seen in hemoglobin.
43
What is the function of **myoglobin**?
Stores and delivers O2 in muscle cells ## Footnote This is particularly important for aquatic animals allowing them to store oxygen while underwater.
44
What is the major protein of **red blood cells**?
Hemoglobin ## Footnote Hemoglobin transports and delivers O2 through the veins and arteries.
45
True or false: **Myoglobin** is a single polypeptide monomer.
TRUE ## Footnote Hemoglobin, in contrast, is a tetramer with four subunits.
46
What percentage identity between myoglobin and hemoglobin is considered homologous?
25% ## Footnote This similarity is enough for the two proteins to be considered homologous based on sequence alone.
47
What happens to myoglobin at a pO2 of 5 torrs?
Releases its O2 ## Footnote This occurs when the last stores of O2 have been depleted.
48
What condition is characterized by not having enough healthy red blood cells to carry oxygen?
Sickle-cell anemia ## Footnote Symptoms include fatigue and pain due to blocked veins/arteries.
49
What is the mutation in **sickle cell hemoglobin (HbS)** compared to normal hemoglobin (HbA)?
A single amino acid difference ## Footnote This occurs in the β-subunit, where Glu is replaced by Val.
50
What type of amino acid substitution occurs in sickle-cell hemoglobin?
Non-conservative substitution ## Footnote This means a change from a polar to a non-polar residue, affecting solubility.
51
What forms a hydrophobic patch on the surface of the mutant protein in sickle-cell disease?
Val β6 ## Footnote This substitution greatly reduces the solubility of the deoxygenated form of hemoglobin.
52
What is the effect of the **Glu to Val** change in hemoglobin?
Causes aggregation and reduced solubility ## Footnote This leads to ineffective transport of O2.
53
Proteins with similar **primary, secondary, and tertiary structures** are considered what?
Homologous ## Footnote Homologous proteins often have similar functions.
54
What do saturation curves indicate about myoglobin and hemoglobin?
Percentage of protein molecules that have oxygen bound ## Footnote The amount varies depending on the partial pressure of O2.
55
What is the term for the loss of the native protein structure due to changes in physical and chemical conditions?
denaturation ## Footnote A denatured protein is biologically inactive.
56
What are the **characteristics of globular proteins** when non-covalent bonds are disrupted?
* Unravel * Lose activity ## Footnote Heat causes side-chains to flex and rotate, breaking van der Waals, hydrogen, and ionic bonds.
57
What is the **inactive precursor form** of insulin called?
Proinsulin ## Footnote It must be cleaved before becoming active.
58
What stabilizes the structure of insulin after it becomes active?
* Disulfide bonds ## Footnote These bonds hold the two separated chains together.
59
What is the role of insulin in the body?
Controls blood glucose levels ## Footnote Diabetes occurs when insulin molecules no longer regulate glucose levels.
60
What type of protein is **collagen**?
Fibrous protein ## Footnote Collagen is not soluble in water and provides mechanical strength.
61
What percentage of the total body protein does collagen make up?
About 30% ## Footnote It is the most abundant protein in vertebrates.
62
What are the **five types of collagen**?
* Collagen I * Collagen II * Collagen III * Collagen IV * Collagen V ## Footnote 90% of the collagen in the body is collagen I.
63
What is the **active form** of collagen called?
Tropocollagen ## Footnote It is synthesized from procollagen.
64
What is the structure of collagen at the molecular level?
Triple-helix structure ## Footnote Each polypeptide chain is colored differently in the helical structure.
65
What amino acid is crucial for the stability of the collagen triple helix?
Glycine ## Footnote Its side-chain is just a hydrogen atom, allowing tight packing.
66
What genetic disorder is associated with a mutation in collagen?
Osteogenesis imperfecta ## Footnote A glycine side chain mutation to cysteine leads to instability.
67
What is **hydroxyproline** and its role in collagen?
A chemically modified amino acid ## Footnote It stabilizes the triple helix through increased hydrogen bonding.
68
What vitamin is essential for the activation of prolyl hydroxylase?
Vitamin C ## Footnote It is necessary for the hydroxylation of proline in collagen.
69
What disease is caused by a lack of vitamin C, affecting collagen strength?
Scurvy ## Footnote It weakens collagen, leading to various health issues.
70
What is the effect of cross-linking in collagen?
Increases strength and reduces solubility ## Footnote Cross-links are formed by covalent bonds between lysine side chains.
71
Proteins are only marginally stable due to the nature of their bonds. True or False?
TRUE ## Footnote Non-covalent bonds hold the 3D structure in place, making proteins susceptible to denaturation.
72
What is the **major function** of fats?
Energy storage ## Footnote This is achieved through the energy stored in their covalent bonds.
73
Where do humans and other mammals store their **fat**?
Adipose cells ## Footnote Adipose tissue cushions vital organs and insulates the body.
74
Lipids do not form large **polymers**. True or False?
TRUE ## Footnote Lipids are a class of large biological molecules.
75
What are the **three biologically important lipids**?
* Fats * Phospholipids * Steroids ## Footnote These lipids are crucial for various biological functions.
76
Fats are constructed from two types of smaller molecules: **glycerol** and _______.
fatty acids ## Footnote Glycerol is a three-carbon alcohol with hydroxyl groups.
77
What type of bond joins the three fatty acids to glycerol in a **triacylglycerol**?
Ester linkage ## Footnote This bond is formed during the assembly of fats.
78
Saturated fatty acids have the maximum number of _______ atoms possible.
hydrogen ## Footnote They contain no double bonds.
79
What is the process of converting unsaturated fats to saturated fats by adding hydrogen called?
Hydrogenation ## Footnote This process can create trans fats, which are harmful.
80
In a **phospholipid**, what forms the hydrophilic head?
Phosphate group ## Footnote The two fatty acid tails are hydrophobic.
81
Phospholipids self-assemble into a **bilayer** when added to water. True or False?
TRUE ## Footnote The hydrophobic tails point inward, while the hydrophilic heads face outward.
82
What is the structure of **steroids** primarily composed of?
Four rings ## Footnote Steroids can also have a small number of polar functional groups.
83
What does DNA direct the synthesis of?
Messenger RNA (mRNA) ## Footnote This process controls protein synthesis.
84
The amino acid sequence of a polypeptide is programmed by a unit of inheritance called a _______.
gene ## Footnote Genes are found within DNA.
85
Nucleic acids are polymers called _______.
polynucleotides ## Footnote Each polynucleotide is made of monomers called nucleotides.
86
What are the two families of **nitrogenous bases**?
* Pyrimidines * Purines ## Footnote Pyrimidines include cytosine, thymine, and uracil; purines include adenine and guanine.
87
In DNA, the sugar is _______; in RNA, the sugar is ribose.
deoxyribose ## Footnote This difference is crucial for the structure and function of nucleic acids.
88
The two backbones of DNA run in opposite _______ directions.
5' → 3' ## Footnote This orientation is referred to as antiparallel.
89
In DNA, adenine (A) pairs with _______ .
thymine ## Footnote Guanine (G) pairs with cytosine (C).
90
The flow of information in genetics is based on a _______ code.
triplet ## Footnote Each triplet, or codon, codes for specific amino acids.
91
Lipids are hydrophobic because they mainly consist of _______ and carbon.
hydrogen ## Footnote This composition makes them not mix well with water.
92
What is the role of **nucleotides** in protein synthesis?
Code for specific amino acids ## Footnote They work together in packets of three (codons).
93
What is **potential energy** stored in?
The food we eat ## Footnote This energy is trapped in chemical bonds and is converted into kinetic energy.
94
Energy can be transferred and transformed, but it cannot be __________.
created or destroyed ## Footnote This principle is fundamental to the laws of thermodynamics.
95
The change in free energy (∆G) during a process is related to which three factors?
* ∆H (enthalpy) * ∆S (entropy) * T (temperature in degrees Kelvin) ## Footnote The equation is ∆G = ∆H - T∆S.
96
Only processes with a __________ ∆G are spontaneous.
negative ## Footnote Spontaneous processes can be harnessed to perform work.
97
If a system goes from more to less order, then the entropy of that system has __________.
increased ## Footnote This is indicated by ΔS > 0.
98
A negative ΔH means a reaction __________ heat to the surroundings.
releases ## Footnote The products have lower energy than the reactants.
99
An **exergonic reaction** proceeds with a net release of free energy and is __________.
spontaneous ## Footnote In contrast, an endergonic reaction absorbs free energy and is not spontaneous.
100
What is ATP and its role in the cell?
ATP (adenosine triphosphate) is the energy shuttle of the cell ## Footnote It powers cellular work by coupling exergonic reactions to endergonic reactions.
101
What are the components of ATP?
* Ribose (a sugar) * Adenine (a nitrogenous base) * Three phosphate groups ## Footnote ATP is crucial for energy transfer in cells.
102
What is the process of **catabolism**?
Release energy by breaking down complex molecules into simpler compounds ## Footnote Cellular respiration is an example of a catabolic pathway.
103
The equation for cellular respiration is __________.
C6H12O6 + 6 O2 → 6 CO2 + 6 H2O + Energy (ATP + heat) ## Footnote This process banks energy in the form of ATP molecules.
104
What are the three stages of **cellular respiration**?
* Glycolysis * Citric acid cycle * Oxidative phosphorylation ## Footnote Each stage plays a crucial role in energy production.
105
What does glycolysis do?
Breaks down glucose into two molecules of pyruvate ## Footnote It harvests chemical energy by converting glucose.
106
What is the role of **electron carriers** in cellular respiration?
Collect hydride ions ## Footnote NADH is an example of an electron carrier that plays a key role in energy transfer.
107
What must pyruvate be converted to before entering the citric acid cycle?
Acetyl CoA ## Footnote This conversion links glycolysis to the citric acid cycle.
108
What does the citric acid cycle complete?
The oxidation of organic fuel ## Footnote It produces a small amount of ATP and supplies electrons for the next stage.
109
What is the importance of breaking bonds in cellular respiration?
To release energy ## Footnote This energy is then used to produce ATP.
110
ATP synthase plays a role in __________.
ATP production ## Footnote It harnesses energy released by falling electrons.
BIOM1051
flashcards
Decks in class (2)
# Cards
Brainscape helps you reach your goals faster, through stronger study habits.
© 2026 Bold Learning Solutions. Terms and Conditions