65 Questions
Which type of cells lack a true nucleus and membrane-bound organelles?
Prokaryotic cells
What are the basic building blocks of proteins?
Amino acids
Which molecule is known as the energy currency of the cell?
ATP
What are the functional groups that show characteristic physical and chemical properties in biomolecules?
Amino and Carboxyl
In the context of biomolecules, what does the term 'polymer' refer to?
Large molecules made up of many repeating units
What is the significance of Friedrich Wöhler's experiment in 1828 concerning organic chemistry?
It demonstrated the synthesis of urea from inorganic compounds.
Which types of cells contain membrane-bound organelles and a true nucleus?
Eukaryotic cells
What role do proteins and nucleic acids play in life processes?
Genetic information storage and transmission
'ATP' is considered as the energy currency of the cell because it:
'Facilitates chemical reactions'
What is the relationship between the nucleotide sequence in nucleic acids and the amino acid sequence in proteins?
Indirect relationship
What was the significance of the discovery of ribozymes?
They showed that RNA can have catalytic activity
What is the main difference between prokaryotes and eukaryotes?
Eukaryotes lack membrane-bound organelles found in prokaryotes
Which statement best describes the catalytic properties of RNA according to the text?
RNA acts as a catalyst in some viruses
What is the meaning of 'prokaryote' based on its Greek derivation?
'Before the nucleus'
Why do prokaryotes not possess membrane-bound organelles like eukaryotes?
Prokaryotes have a simpler structure than eukaryotes
What function do ribozymes perform?
Catalyze chemical reactions
What role did Thomas R. Cech and Sidney Altman play in RNA research?
Discovered the catalytic properties of RNA
'Eukaryote' originates from the Greek words meaning:
'True nucleus'
Which type of cells have a well-defined nucleus surrounded by a nuclear membrane?
Eukaryotic cells
What is the ultimate source of energy for all life on earth?
Light from the sun
In biochemical energetics, what happens if ΔG is greater than 0?
The reaction will not occur unless energy is supplied from an external source
What type of reactions are favored: Exothermic/Exergonic or Endothermic/Endergonic?
Exothermic/Exergonic reactions
Which type of organisms use light energy to drive the synthesis of carbohydrates?
Photosynthetic organisms
In terms of energetics, what does a negative ΔG indicate?
The reaction is spontaneous
In biological macromolecules, what is the 'sense' or directionality that they possess?
Both N-terminus and C-terminus
What is the correct statement regarding the linkages in polysaccharides starch and cellulose?
Starch has α-C1 to C4 linkages while cellulose has βC1 to C4 linkages.
What type of bond is formed between the 3'-OH of ribose ring of one nucleotide and the 5'-OH of ribose ring of a neighboring nucleotide in nucleic acids?
Phosphodiester bond
Which of the following statements about enzymes is true?
Enzymes are a class of proteins (and RNA) that display catalytic activity.
What occurs when the 5' group of a nucleotide triphosphate interacts with the free 3' hydroxyl group of a nucleotide chain?
A new phosphodiester bond is formed
Which type of linkage is observed in the polysaccharide starch?
α-C1toC4
What is the correct order of amino acids in the sequence Ser-Val-Tyr-Cys?
Serine - Tyrosine - Valine - Cysteine
What happens when the bond between the first phosphorus atom and the oxygen atom linking it to the next phosphate group breaks?
Formation of new phosphodiester bond
What is the significance of the sense of directionality in biological macromolecules?
Affects the function and properties of macromolecules
Which type of linkages are observed in both starch and cellulose?
α-C1toC4 in starch, β-C1toC4 in cellulose
What happens when the 3' hydroxyl group of one nucleotide forms a bond with the 5' oxygen atom of another nucleotide in a nucleic acid chain?
A phosphodiester bond is formed
What is the role of enzymes that display catalytic activity according to the text?
Speeding up chemical reactions
In nucleic acids, which ribose ring atom forms a bond with the 5'-OH of a neighboring nucleotide's ribose ring?
3'-OH
What characteristic distinguishes Ser-Val-Tyr-Cys from Cys-Tyr-Val-Ser?
Directionality of peptide bonds
What is the significance of the directionality possessed by biological macromolecules?
Impacts their structural conformation
Which statement best describes the linkages in starch and cellulose as mentioned in the text?
Starch: α-glycosidic, Cellulose: β-glycosidic
'ATP' is considered the energy currency of the cell primarily because it:
Stores energy in chemical bonds
What type of linkage is observed in the polysaccharide cellulose?
Beta-1,4-glycosidic bonds
What is the significance of the directionality in biological macromolecules?
It determines the type of cellular processes the molecule can participate in
Which nucleotide is complementary to adenine in a DNA molecule?
Thymine
Enzymes increase the rate of a reaction by:
Decreasing the activation energy
What is the role of tRNA in protein synthesis?
Binding amino acids and matching them to codons on mRNA
What does the genetic code dictate in protein synthesis?
The order of amino acids in a protein
How do enzymes achieve specificity in catalyzing reactions?
By changing their shape to fit the substrate
What is the significance of phosphodiester linkages in nucleic acids?
They stabilize the sugar-phosphate backbone of nucleic acids
What is the main difference in the linkages observed in the polysaccharides starch and cellulose?
Starch contains alpha 1-4 glycosidic linkages, while cellulose contains beta 1-4 glycosidic linkages.
In terms of biological macromolecules, what does the 'sense' of directionality mean?
It indicates the orientation of the molecule in terms of its beginning and end points.
Which statement best describes the relationship between the genetic code and the amino acid sequence?
The genetic code is a set of rules that define how the sequence of nucleotides in DNA corresponds to a specific amino acid sequence in proteins.
What is a key characteristic of enzymes related to their catalytic activity?
Enzymes accelerate chemical reactions by lowering activation energy.
What is the primary role of nucleic acids in relation to the amino acid sequence of proteins?
Nucleic acids store and transmit genetic information that determines the amino acid sequence of proteins.
Why is it significant that RNA has been considered the original coding material by many scientists?
RNA can catalyze its own processing without the need for enzymes.
What contributes significantly to the catalytic effectiveness of an enzyme?
The specific amino acid sequence of the enzyme.
Why do certain types of RNA like ribozymes have gained recognition for their catalytic activity?
They are capable of facilitating specific chemical reactions within cells.
What did Thomas R. Cech and Sidney Altman receive the Nobel Prize in Chemistry for in 1989?
The elucidation of the catalytic properties of RNA molecules.
What type of linkage is observed in the polysaccharide cellulose?
Beta-1,4-glycosidic linkage
In biological macromolecules, what does the term 'directionality' refer to?
The sequence of monomers in the polymer
How is the genetic code related to the amino acid sequence in proteins?
Each codon encodes for a specific protein structure
What do enzymes primarily do in biochemical reactions?
Lower the activation energy of reactions
Which of the following statements best describes the catalytic properties of ribozymes?
Ribozymes are RNA molecules that can catalyze chemical reactions
The bond between the 3'-OH group of one nucleotide and the 5'-phosphate group of the next nucleotide in DNA molecules is known as:
Phosphodiester bond
What is the significance of the arrangement of functional groups in biological macromolecules?
Impacts the polarity of macromolecules
Study Notes
Biomolecules and Biochemistry
- Biomolecules are molecules produced in living organisms, and their reactions can be described by the methods of organic chemistry.
- The experiment of Friedrich Wöhler in 1828 demonstrated the possibility of synthesizing organic compounds from inorganic substances.
Functional Groups
- A functional group is an atom or group of atoms that show characteristic physical and chemical properties.
- Examples of functional groups include phosphoester and phosphoanhydride in ATP, which is considered the energy currency of the cell.
Origins of Life
- The "big bang" theory proposes that all matter was originally confined in a very small space, which expanded with great force, and has been decreasing in temperature ever since.
- In the earliest stages of the universe, only H, He, and Li were present, with other elements formed by thermonuclear reactions in stars.
- Gases present in the early earth's atmosphere included NH3, H2S, CO, CO2, CH4, N2, H2, and H2O, from which biomolecules could have arisen under abiotic conditions.
Directionality in Macromolecules
- Biological macromolecules and their building blocks have a "sense" or directionality, with a clear N-terminus and C-terminus.
- Examples of directional macromolecules include proteins, polysaccharides, and nucleic acids.
Enzymes and Catalytic Activity
- Enzymes are a class of proteins (and RNA) that display catalytic activity, with the catalytic effectiveness depending on their amino acid sequence.
- Some types of RNA have catalytic activity (ribozymes), capable of catalyzing their own further processing.
- The discovery of catalytic properties of RNA earned Thomas R. Cech and Sidney Altman the Nobel Prize in chemistry in 1989.
Prokaryotes and Eukaryotes
- Prokaryotes are single-celled organisms, lacking a well-defined nucleus, including bacteria and archae.
- Eukaryotes are organisms with a true nucleus, surrounded by a nuclear membrane, and can be single-celled or multicellular.
Biochemical Energetics
- All cells require energy to function, with light from the sun being the ultimate source of energy for all life on earth.
- The energetics of a chemical reaction depends on the free energy change (ΔG), with spontaneous reactions having ΔG < 0 and non-spontaneous reactions having ΔG > 0.
- Exergonic reactions are favored, while endergonic reactions are not favored, unless energy is supplied from an external source.
This quiz covers the fundamental concepts of biochemistry including functional groups, biomolecules, macromolecules, origins of life, prokaryotes vs. eukaryotes, kingdoms and domains, biochemical energetics, levels of structural organization in the human body, and the chemical foundations of biochemistry. It also includes an overview of organic chemistry and its relevance to biochemistry.
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