Lecture 1 Flashcards
Quiz prep
Which of the following best defines a cell?
A) Ability to generate energy through photosynthesis
B) Capability to create complex organisms
C) Smallest unit capable of independent life and forming all living organisms and body tissues
D) Role in genetic variation
E) Potential to execute complex mathematical computations
The smallest unit capable of of independent life and forming all living organisms and body tissues
What is the typical size range of cells?
A) Between 1 and 100 cm in diameter
B) Between 1 and 100 μm in diameter
C) Between 1 and 100 nm in diameter
D) Between 1 and 100 mm in diameter
E) Between 1 and 100 Ångströms in diameter
Between 1 and 100 μm in diameter
How do biologists examine cells?
A) With naked eyes
B) Through telescopes
C) Using sonar technology
D) By employing microscopes
E) Through chemical reactions
By employing microscopes
Which type of light do light microscopes utilize for observation?
A) Infrared light
B) Ultraviolet light
C) Visible light
D) X-rays
E) Gamma rays
Visible light
What do fluorescent light microscopes capture?
A) Radio waves
B) Infrared light
C) Ultraviolet light
D) Fluorescence
E) Heat radiation
Fluorescence
Question 6: What are the two main types of electron microscopes?
A) Light electron microscopes and dark electron microscopes
B) Transparent electron microscopes and opaque electron microscopes
C) X-ray electron microscopes and gamma-ray electron microscopes
D) Transmission electron microscopes and Scanning electron microscopes
E) Reflective electron microscopes and refractive electron microscopes
Transmission electron microscopes and Scanning electron microscopes
What does a transmission electron microscope (TEM) study?
A) Surface textures of cells
B) Cell fluorescence
C) The internal structure of thin sections of cells
D) Cell growth patterns
E) The movement of organelles within cells
The internal structure of thin sections of cells
What is the primary purpose of a scanning electron microscope (SEM)?
A) Studying DNA structure
B) Analyzing cell division
C) Investigating cell metabolism
D) Studying the fine details of cell surfaces
E) Observing intracellular transport
Studying the fine details of cell surfaces
What are macromolecules composed of?
A) Amino acids only
B) Simple sugars only
C) Nucleotides only
D) Polysaccharides (sugars), Lipids, Nucleic acids (DNA, RNA), and Proteins
E) Fatty acids and nucleotides
Polysaccharides (sugars), Lipids, Nucleic acids (DNA, RNA), and Proteins
What constitutes the majority of a cell’s composition?
A) Large molecules
B) Carbohydrates
C) Lipids
D) Water
E) Proteins
Water
Which categories do large molecules predominantly fall under?
A) Carbohydrates only
B) Proteins only
C) Nucleic acids only
D) Lipids or polymers
E) Amino acids or nucleotides
Lipids or polymers
What distinguishes lipids from true polymers?
A) Their hydrophilic nature
B) Their tendency to form double bonds
C) Their inability to bond covalently
D) They are not composed of monomers
E) Their classification as macromolecules
They are not composed of monomers
What is the defining characteristic of macromolecules like carbohydrates, proteins, and nucleic acids?
A) Their color under a microscope
B) Their reactivity with acids
C) Their small molecular size
D) Their significant size on the molecular scale
E) Their formation of hydrogen bonds
Their significant size on the molecular scale
What are macromolecules primarily made of?
A) Nucleotides
B) Amino acids
C) Monomers
D) Polymers
E) Hydrocarbons
Monomers
What constitutes a polymer?
A) A collection of dissimilar molecules
B) A small molecule linked to a larger molecule
C) A molecule consisting of atoms of various elements
D) A long molecule made up of similar or identical building blocks linked by covalent bonds
E) A molecule with alternating single and double bonds
A long molecule made up of similar or identical building blocks linked by covalent bonds
How do polymers increase in size?
A) By joining larger molecules together
B) By releasing water molecules
C) By disassembling monomers
D) Through dehydration reactions
E) By forming ionic bonds
Through dehydration reactions
What is the reverse process of dehydration called?
A) Condensation
B) Polymerization
C) Oxidation
D) Hydrolysis
E) Fusion
Hydrolysis
What does hydrolysis involve?
A) Formation of water molecules
B) Dehydration of polymers
C) Hydrogen bonding
D) The addition of water to break covalent bonds
E) Carbon bonding
The addition of water to break covalent bonds
What role do polysaccharides play in organisms?
A) Formation of genetic material
B) Regulation of cellular processes
C) Storage of amino acids
D) Serving as fuel and building material
E) Catalyzing chemical reactions
Serving as fuel and building material
What is a characteristic feature of monosaccharides’ molecular formulas?
A) Containing only carbon and oxygen
B) Being multiples of CH4
C) Always being pentose sugars
D) Being some multiple of the unit CH2O
E) Having linear structures
D) Being some multiple of the unit CH2O
What linkage joins two monosaccharides to form a disaccharide?
A) Peptide linkage
B) Ionic linkage
C) Hydrogen bond
D) Glycosidic linkage
E) Ester linkage
Glycosidic linkage
What describes the structure of polysaccharides?
A) Individual monosaccharides linked by peptide bonds
B) Chains of nucleotides connected by glycosidic linkages
C) Polymers with a few monosaccharides linked by covalent bonds
D) Polymers with a few hundred to a few thousand monosaccharides joined by glycosidic linkages
E) Polymers with alternating sugar and phosphate groups
Polymers with a few hundred to a few thousand monosaccharides joined by glycosidic linkages
How do both plants and animals store sugars?
A) In the form of nucleotides
B) As structural polysaccharides
C) As storage polysaccharides
D) In the form of amino acids
E) Through peptide bonds
As storage polysaccharides
What do animals store as a storage polysaccharide?
A) Starch
B) Cellulose
C) Amylopectin
D) Glycogen
E) Amylose
Glycogen
What do plants store as a storage polysaccharide?
A) Starch
B) Glycogen
C) Chitin
D) Cellulose
E) Collagen
Starch
What purpose do structural polysaccharides serve in organisms?
A) Energy storage
B) Enzyme activation
C) Building strong materials
D) DNA replication
E) Cellular respiration
Building strong materials
How do differing glycosidic linkages affect starch and cellulose?
A) They result in identical structures
B) They create similar three-dimensional shapes
C) They make cellulose flexible
D) They give the two molecules distinct three-dimensional shapes
E) They convert starch into cellulose
D) They give the two molecules distinct three-dimensional shapes
What characterizes lipids as a group?
A) Hydrophilic nature
B) Rapid solubility in water
C) Their tendency to form hydrogen bonds
D) Diversity and hydrophobic nature
E) Formation of peptide bonds
D) Diversity and hydrophobic nature
Why are lipids grouped?
A) Due to their similar structures
B) Because they all contain fatty acids
C) Because they are all polar molecules
D) Because they share a hydrophilic nature
E) Because they share a hydrophobic nature and mix poorly with water
Because they share a hydrophobic nature and mix poorly with water
What components do lipids primarily constitute?
A) DNA and RNA
B) Carbohydrates
C) Cellulose
D) Cell membranes
E) Polypeptides
Cell membranes
What are the main categories of lipids?
A) Amino acids, fatty acids, and nucleotides
B) Carbohydrates, peptides, and nucleic acids
C) Fats, peptides, and steroids
D) Fats, phospholipids, and steroids
E) Monosaccharides, triglycerides, and polypeptides
Fats, phospholipids, and steroids
What are the two main constituents of a fat molecule?
A) Carbohydrates and lipids
B) Amino acids and nucleotides
C) Glycerol and nucleic acids
D) Glycerol and fatty acids
E) Peptides and sugars
Glycerol and fatty acids
What is the structure of triacylglycerols?
A) A glycerol molecule joined to three fatty acid molecules
B) A glycerol molecule joined to two fatty acid molecules
C) A glycerol molecule joined to a single fatty acid molecule
D) A glycerol molecule bonded to a carbohydrate molecule
E) A glycerol molecule bonded to a phosphate group
A glycerol molecule joined to three fatty acid molecules
How are phospholipids structured differently from triacylglycerols?
A) Phospholipids have three fatty acids
B) Phospholipids have a single fatty acid
C) Phospholipids have no fatty acids
D) Phospholipids have two fatty acids and a phosphate group
E) Phospholipids have a glycerol molecule bonded to a protein
Phospholipids have two fatty acids and a phosphate group
What do the terms “saturated fats” and “unsaturated fats” refer to?
A) The levels of hydrogen in the molecule
B) The types of fatty acids present
C) The types of bonds in the fatty acids
D) The structure of the glycerol backbone
E) The structure of the hydrocarbon chains of the fatty acids
The structure of the hydrocarbon chains of the fatty acids
What is a distinguishing feature of a phospholipid?
A) Three hydrophilic heads and one hydrophobic tail
B) A hydrophobic head and two hydrophilic tails
C) Two hydrophobic heads and one hydrophilic tail
D) A hydrophilic (polar) head and two hydrophobic (nonpolar) tails
E) An equal distribution of hydrophilic and hydrophobic components
A hydrophilic (polar) head and two hydrophobic (nonpolar) tails
What is the main role of phospholipids in the cell?
A) They store genetic information
B) They serve as energy reserves
C) They are vital for enzymatic reactions
D) They are major constituents of cell membranes
E) They catalyze protein synthesis
They are major constituents of cell membranes
What defines steroids as a type of lipid?
A) A long carbon chain
B) A carbon skeleton without fused rings
C) A carbohydrate skeleton consisting of three fused rings
D) A carbon skeleton consisting of four fused rings
E) A linear arrangement of carbon atoms
A carbon skeleton consisting of four fused rings
What are proteins composed of?
A) Amino acids
B) Monosaccharides
C) Nucleotides
D) Fatty acids
E) Glycerol and phosphate groups
Amino acids
What contributes to the diverse functions of proteins?
A) Their simple and uniform structures
B) Their preference for specific locations in cells
C) Their formation of helical structures
D) A variety of structures resulting in a wide range of functions
E) Their ability to catalyze any chemical reaction
A variety of structures resulting in a wide range of functions
How do proteins influence cellular processes?
A) They provide energy
B) They transport water
C) They mediate and regulate most cellular activities
D) They produce genetic material
E) They synthesize lipids
They mediate and regulate most cellular activities
What proportion of the dry mass of most cells do proteins account for?
A) Less than 10%
B) Around 25%
C) Over 50%
D) About 75%
E) 100%
Over 50%
What role do enzymatic proteins play?
A) Providing structural support
B) Storing amino acids
C) Accelerating specific chemical reactions
D) Transporting substances
E) Regulating DNA replication
Accelerating specific chemical reactions
What are antibodies?
A) Carbohydrates
B) Lipids
C) Nucleic acids
D) Proteins
E) Hormones
Proteins
How do storage proteins function?
A) Catalyzing reactions
B) Providing energy
C) Regulating gene expression
D) Serving as a source of amino acids
E) Transporting ions
Serving as a source of amino acids
What role do proteins play in the transport of substances?
A) Creating energy
B) Mediating the selective transport of substances
C) Storing genetic information
D) Catalyzing chemical reactions
E) Regulating cell division
Mediating the selective transport of substances
What characterizes an amino acid?
A) It is a monosaccharide
B) It has a fatty acid chain
C) It contains a phosphate group
D) It has both an amino group and a carboxyl group
E) It is a nucleotide
It has both an amino group and a carboxyl group
What common features do all amino acids share?
A) They all contain fatty acid chains
B) They all have phosphate groups
C) They all possess hydroxyl groups
D) They all have both amino and carboxyl groups
E) They all have nucleotide backbones
They all have both amino and carboxyl groups
How many different amino acids makeup proteins?
A) 10
B) 15
C) 20
D) 25
E) 30
20
What is the fundamental building block of proteins?
A) Carbohydrates
B) Fatty acids
C) Monosaccharides
D) Amino acids
E) Nucleotides
Amino acids
What is the name of the bond that forms between amino acids in a polypeptide chain?
A) Hydrogen bond
B) Ionic bond
C) Covalent bond
D) Peptide bond
E) Phosphodiester bond
Hydrogen bond
How many levels of protein structure are there?
A) Two
B) Three
C) Four
D) Five
E) Six
Four
What does the primary structure of a protein refer to?
A) Overall three-dimensional shape
B) Regions stabilized by hydrogen bonds
C) Sequence of amino acids
D) Interaction between subunits
E) Secondary structure patterns
Sequence of amino acids
What is the main stabilizing force in the secondary structure of proteins?
A) Covalent bonds
B) Hydrogen bonds
C) Ionic bonds
D) Van der Waals interactions
E) Phosphodiester bonds
Hydrogen bonds
Which structures are the predominant secondary structures in proteins?
A) Alpha helices only
B) Beta-strands only
C) Both alpha helices and beta-strands
D) Beta-sheets only
E) Random coils only
Both alpha helices and beta-strands
What does the tertiary structure of a protein refer to?
A) Sequence of amino acids
B) Overall shape resulting from interactions between amino acids
C) Stabilized by hydrogen bonds
D) The covalent bond between amino acids
E) The formation of alpha helices and beta-strands
Overall shape resulting from interactions between amino acids
What is the quaternary structure of proteins?
A) The secondary structure
B) The tertiary structure
C) The overall shape of a polypeptide
D) The aggregation of two or more polypeptide chains
E) The formation of alpha helices and beta-strands
The aggregation of two or more polypeptide chains
What is the primary role of nucleic acids?
A) Energy storage
B) Enzyme catalysis
C) Structural support
D) Storing, transmitting, and expressing hereditary information
E) Protein synthesis
Storing, transmitting, and expressing hereditary information
What are the two main types of nucleic acids?
A) Adenosine and guanosine
B) Deoxyribonucleic acid (DNA) and ribonucleic acid (RNA)
C) Proteins and lipids
D) Carbohydrates and nucleotides
E) Amino acids and peptides
Deoxyribonucleic acid (DNA) and ribonucleic acid (RNA)
What is the sequence of genetic information flow in a eukaryotic cell?
A) DNA → Protein → RNA
B) Protein → DNA → RNA
C) RNA → DNA → Protein
D) DNA → RNA → Protein
E) RNA → Protein → DNA
DNA → RNA → Protein
Where is genetic information stored in a eukaryotic cell?
A) Nucleus
B) Cytoplasm
C) Mitochondria
D) Chloroplasts
E) Nucleus, mitochondria, and chloroplasts
Nucleus
What are the monomers of nucleic acids called?
A) Amino acids
B) Nucleotides
C) Monosaccharides
D) Peptides
E) Polynucleotides
Nucleotides
What are the three components of a nucleotide?
A) A nitrogenous base, a six-carbon sugar, and a phosphate group
B) A phosphate group, a five-carbon sugar, and a sulfur atom
C) A nitrogenous base, a five-carbon sugar, and one phosphate group
D) A purine base, a five-carbon sugar, and an oxygen atom
E) A methyl group, a three-carbon sugar, and a hydrogen atom
A nitrogenous base, a five-carbon sugar, and one phosphate group
What is the term for the arrangement in which DNA molecules have two polynucleotide strands winding around each other?
A) Covalent linkage
B) Secondary structure
C) Antiparallel arrangement
D) Helical twist
E) Base pairing
Antiparallel arrangement
How do the sugar-phosphate backbones of DNA strands run?
A) In the same 5’ → 3’ direction
B) In opposite 3’ → 5’ directions
C) In opposite 5’ → 3’ directions
D) In the same 3’ → 5’ direction
E) In parallel 5’ → 3’ directions
In opposite 5’ → 3’ directions
How does base pairing occur in RNA molecules?
A) Between two separate RNA molecules
B) Between RNA and DNA molecules
C) Between the sugar-phosphate backbones of RNA molecules
D) Between stretches of nucleotides in the same RNA molecule
E) Between RNA and protein molecules
Between stretches of nucleotides in the same RNA molecule
Which bases pair with each other in DNA?
A) Adenine (A) with guanine (G), and cytosine (C) with uracil (U)
B) Guanine (G) with thymine (T), and adenine (A) with uracil (U)
C) Cytosine (C) with adenine (A), and guanine (G) with uracil (U)
D) Adenine (A) with thymine (T), and guanine (G) with cytosine (C)
E) Thymine (T) with uracil (U), and adenine (A) with cytosine (C)
Adenine (A) with thymine (T), and guanine (G) with cytosine (C)
What is the primary distinction between eukaryotic and prokaryotic cells?
A) Eukaryotic cells lack a nucleus
B) Eukaryotic cells lack internal membranes
C) Prokaryotic cells lack DNA
D) Eukaryotic cells have a true nucleus and internal membranes
E) Prokaryotic cells have a true nucleus and internal membranes
Eukaryotic cells have a true nucleus and internal membranes
Where is the DNA concentrated in a prokaryotic cell?
A) In the nucleus
B) In the cytoplasm
C) In membrane-enclosed organelles
D) In a region called the nucleoid
E) In the mitochondria
In a region called the nucleoid
Where is most of the DNA in a eukaryotic cell found?
A) In the cytoplasm
B) In the mitochondria
C) In membrane-enclosed organelles
D) In a region called the nucleoid
E) In an organelle called the nucleus
In an organelle called the nucleus
What term is used to describe the region between the nucleus and the plasma membrane of a cell?
A) Nucleoid
B) Nucleus
C) Cytoplasm
D) Organelle
E) Membrane-enclosed region
Cytoplasm
What constitutes the plasma membrane and the membranes of organelles?
A) Double layers of carbohydrates
B) A single layer of lipids
C) Double layers of proteins
D) Double layers of phospholipids
E) A combination of lipids and proteins
A combination of lipids and proteins