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
How are the hydrophobic and hydrophilic parts of phospholipids arranged in a membrane?
A) Hydrophobic parts are exposed to the aqueous solutions
B) Hydrophilic parts are in contact with the interior of the membrane
C) Hydrophobic parts are in contact with the aqueous solutions
D) Both hydrophilic and hydrophobic parts are exposed
E) Both hydrophilic and hydrophobic parts are inside the membrane
Both hydrophilic and hydrophobic parts are inside the membrane
What can be found attached to proteins or lipids on the outer surface of the plasma membrane?
A) DNA molecules
B) Hydrophobic chains
C) Hydrophilic regions
D) Carbohydrate side chains
E) Lipid bilayers
Carbohydrate side chains
What is the term for a molecule that has both a hydrophilic and a hydrophobic region?
A) Bipolar molecule
B) Amphipathic molecule
C) Monopolar molecule
D) Hydrophilic molecule
E) Hydrophobic molecule
Amphipathic molecule
How is the structure of the cell membrane described in the fluid mosaic model?
A) A rigid structure of proteins embedded in a lipid bilayer
B) A fluid bilayer of phospholipids with embedded protein molecules
C) A static arrangement of lipids and proteins
D) A layered arrangement of proteins with lipid molecules on the surface
E) A complex network of carbohydrates interspersed with protein molecules
A fluid bilayer of phospholipids with embedded protein molecules
Where are the eukaryotic cell’s genetic instructions stored?
A) In the mitochondria
B) In the cytoplasm
C) In the ribosomes
D) In the nucleus
E) In the endoplasmic reticulum
In the nucleus
What role do ribosomes play in protein synthesis?
A) They store genetic instructions
B) They house the cell’s DNA
C) They synthesize nucleotides
D) They carry out protein synthesis
E) They enclose the nucleus
They carry out protein synthesis
What process occurs in the nucleus?
A) Protein synthesis
B) Energy production
C) Photosynthesis
D) Transcription
E) Translation
Transcription
Where does protein synthesis occur?
A) In the mitochondria
B) In the nucleus
C) In the ribosomes
D) In the lysosomes
E) In the cytoplasm
In the ribosomes
What is the function of the nuclear envelope?
A) To enclose the ribosomes
B) To store genetic instructions
C) To produce energy
D) To separate the nucleus from the cytoplasm
E) To carry out protein synthesis
To separate the nucleus from the cytoplasm
How is the nuclear envelope structured?
A) It is composed of a single membrane
B) It consists of a rigid layer of proteins
C) It is a mosaic of lipid molecules
D) It is composed of two membranes
E) It is made up of carbohydrates and proteins
It is composed of two membranes
What structures regulate the entry and exit of molecules from the nucleus?
A) Nuclear pores
B) Ribosomes
C) Nucleoli
D) Lysosomes
E) Endoplasmic reticulum
Nuclear pores
What is the nucleolus responsible for synthesizing?
A) DNA molecules
B) Messenger RNA (mRNA)
C) Transfer RNA (tRNA)
D) Ribosomal RNA (rRNA)
E) Proteins
Ribosomal RNA (rRNA)
What cellular components are responsible for protein synthesis?
A) Nucleoli
B) Nuclei
C) Mitochondria
D) Ribosomes
E) Lysosomes
Ribosomes
What are ribosomes composed of?
A) One subunit
B) Three subunits
C) A single-component
D) Large and Small subunits
E) Nucleotides and amino acids
Large and Small subunits
Where do ribosomes build proteins in a cell?
A) In the nucleus
B) In the cytoplasm
C) In the endoplasmic reticulum
D) Both in the cytosol and attached to the endoplasmic reticulum or nuclear envelope
E) In the mitochondria
Both in the cytosol and attached to the endoplasmic reticulum or nuclear envelope
Are there any structural differences between bound and free ribosomes?
A) Yes, bound ribosomes are smaller
B) No, they are structurally identical
C) Yes, free ribosomes have an additional subunit
D) Yes, bound ribosomes have a different shape
E) No, they are made of different types of proteins
No, they are structurally identical
What type of proteins are made on free ribosomes?
A) Membrane proteins
B) Secreted proteins
C) Proteins that function within the cytosol
D) Ribosomal proteins
E) RNA-binding proteins
Proteins that function within the cytosol
What is the main function of mitochondria?
A) Protein synthesis
B) Photosynthesis
C) Cellular respiration
D) Lipid synthesis
E) DNA replication
Cellular respiration
What is the role of chloroplasts in plants and algae?
A) Cellular respiration
B) Protein synthesis
C) Photosynthesis
D) ATP synthesis
E) Lipid metabolism
Photosynthesis
What is the purpose of the two membranes surrounding mitochondria and chloroplasts?
A) To protect them from external influences
B) To facilitate protein synthesis
C) To separate them from other organelles
D) To regulate energy conversion
E) To provide a barrier for compartmentalization and energy conversion
To provide a barrier for compartmentalization and energy conversion
What do mitochondria primarily use cellular respiration for?
A) ATP synthesis
B) DNA replication
C) Photosynthesis
D) Protein synthesis
E) Extracting energy from sugars, fats, and other fuels
Extracting energy from sugars, fats, and other fuels
What components do both mitochondria and chloroplasts contain that are also present in prokaryotes?
A) Nuclei
B) Ribosomes
C) Endoplasmic reticulum
D) Golgi apparatus
E) Lysosomes
Ribosomes
What does the endosymbiont theory propose about the origin of eukaryotic cells?
A) Eukaryotic cells evolved from prokaryotic cells
B) Eukaryotic cells evolved from a fusion of multiple prokaryotic cells
C) An early ancestor of eukaryotic cells engulfed a non-photosynthetic prokaryotic cell and established an endosymbiotic relationship
D) Eukaryotic cells originated directly from a primordial soup
E) Prokaryotic cells originated from eukaryotic cells
An early ancestor of eukaryotic cells engulfed a non-photosynthetic prokaryotic cell and established an endosymbiotic relationship
What were the ancestors of mitochondria and chloroplasts?
A) Non-oxygen-using, non-photosynthetic prokaryotes
B) Oxygen-using, non-photosynthetic prokaryotes
C) Oxygen-using, photosynthetic prokaryotes
D) Non-oxygen using, photosynthetic prokaryotes
E) Eukaryotic cells
Oxygen-using, non-photosynthetic prokaryotes
How is the inner membrane of mitochondria structured?
A) Smooth and even
B) Convex with infoldings called cristae
C) Rigid and flat
D) Covered in ribosomes
E) Smooth with matrix-like patterns
Convex with infoldings called cristae
What can be found in the matrix of mitochondria?
A) Ribosomes only
B) Mitochondrial DNA only
C) Enzymes for photosynthesis
D) Both mitochondrial DNA and ribosomes
E) Chlorophyll molecules
Both mitochondrial DNA and ribosomes
How do mitochondria typically behave in terms of fusion and division?
A) They remain static and never divide
B) They constantly undergo division, but not fusion
C) They constantly undergo fusion, but not division
D) They fuse, divide, and are very dynamic
E) They undergo fusion and division, but not simultaneously
They fuse, divide, and are very dynamic
What is the primary role of chloroplasts?
A) ATP synthesis
B) Cellular respiration
C) Photosynthetic production of sugar
D) Protein synthesis
E) DNA replication
Photosynthetic production of sugar
What term is used to describe colorless organelles that store starch?
A) Chromoplast
B) Leucoplast
C) Chloroplast
D) Amyloplast
E) Peroxisome
Amyloplast
What molecules are contained within chloroplasts that function in photosynthesis?
A) Enzymes for cellular respiration
B) Chlorophyll pigment and enzymes for photosynthetic sugar production
C) Ribosomal RNA and DNA
D) Starch molecules
E) Peroxides and fatty acids
Chlorophyll pigment and enzymes for photosynthetic sugar production
What is the function of peroxisomes?
A) To store starch
B) To produce chlorophyll
C) To generate ATP
D) To break down fatty acids
E) To perform photosynthesis
To break down fatty acids
Question: What are the primary functions of the endomembrane system in a cell?
A) Energy production and ATP synthesis
B) DNA replication and protein synthesis
C) Regulating protein traffic and performing metabolic functions
D) Photosynthesis and carbohydrate storage
E) Cell division and waste elimination
C) Regulating protein traffic and performing metabolic functions
Question: Which organelles are part of the endomembrane system in a eukaryotic cell?
A) Mitochondria and chloroplasts
B) Nucleus and cytoplasm
C) Golgi apparatus and ribosomes
D) Nuclear envelope, endoplasmic reticulum, Golgi apparatus, lysosomes, vesicles, vacuoles, and plasma membrane
E) Nucleus and nucleolus
D) Nuclear envelope, endoplasmic reticulum, Golgi apparatus, lysosomes, vesicles, vacuoles, and plasma membrane
Question: How are the different organelles of the endomembrane system related?
A) They are connected by direct physical continuity
B) They are connected by a shared cytoplasm
C) They are connected by a common membrane
D) They are related either through direct physical continuity or by the transfer of membrane segments as tiny vesicles
E) They are unrelated and function independently
D) They are related either through direct physical continuity or by the transfer of membrane segments as tiny vesicles
Question: What is the structural composition of the endoplasmic reticulum (ER)?
A) Membranous tubules and sacs called cisternae
B) Solid, compact layers of protein
C) A single, continuous membrane
D) Rigid, crystal-like structures
E) A network of protein filaments
A) Membranous tubules and sacs called cisternae
Question: What distinguishes the smooth endoplasmic reticulum (ER) from the rough endoplasmic reticulum (ER)?
A) Smooth ER has ribosomes, while rough ER lacks them
B) Smooth ER lacks ribosomes, while rough ER has them
C) Smooth ER is involved in photosynthesis, while rough ER is not
D) Smooth ER is found in animal cells, while rough ER is found in plant cells
E) Smooth ER has a more convoluted structure than rough ER
B) Smooth ER lacks ribosomes, while rough ER has them
Question: What are ribosomes primarily responsible for in a cell?
A) Energy production
B) DNA replication
C) Carbohydrate synthesis
D) Protein synthesis
E) Lipid metabolism
D) Protein synthesis
Question: Where do ribosomes build proteins in a cell?
A) In the mitochondria
B) In the nucleus
C) In the endoplasmic reticulum
D) Both in the cytosol and attached to the endoplasmic reticulum or nuclear envelope
E) In the lysosomes
D) Both in the cytosol and attached to the endoplasmic reticulum or nuclear envelope
Question: Are bound and free ribosomes structurally identical?
A) Yes
B) No
C) Bound ribosomes are larger
D) Free ribosomes are more complex
E) Bound ribosomes lack ribosomal RNA
A) Yes
Question: What are some functions of the smooth endoplasmic reticulum (ER)?
A) Protein synthesis
B) Energy production
C) DNA replication
D) Synthesis of lipids, metabolism of carbohydrates, detoxification of drugs, and storage of calcium ions
E) Photosynthesis
D) Synthesis of lipids, metabolism of carbohydrates, detoxification of drugs, and storage of calcium ions
Question: What types of proteins are primarily synthesized by the rough endoplasmic reticulum (ER)?
A) Enzymes for energy production
B) Membrane proteins and secreted proteins
C) Chlorophyll molecules
D) DNA-binding proteins
E) Ribosomal proteins
B) Membrane proteins and secreted proteins
Question: Where are the proteins made by ribosomes on the rough endoplasmic reticulum (RER) transported to?
A) Nucleus
B) Cytoplasm
C) Golgi apparatus
D) Lysosomes
E) Lumen of the ER
E) Lumen of the ER
Question: How do secretory proteins depart from the endoplasmic reticulum (ER)?
A) They diffuse out of the ER membrane
B) They are transported by motor proteins
C) They are carried in vesicles called transport vesicles
D) They exit through nuclear pores
E) They are directly released into the cytosol
C) They are carried in vesicles called transport vesicles
Question: What are most secretory proteins covalently bonded to?
A) Lipids
B) Nucleic acids
C) Carbohydrates
D) Amino acids
E) Peptides
C) Carbohydrates
Question: Where are carbohydrates attached to proteins in the endoplasmic reticulum (ER)?
A) Cytosol
B) Nucleus
C) Golgi apparatus
D) Mitochondria
E) ER lumen
E) ER lumen
Question: What function does the rough endoplasmic reticulum (ER) serve in addition to making secretory proteins?
A) ATP synthesis
B) Photosynthesis
C) Detoxification of drugs
D) Membrane factory for the cell
E) Carbohydrate synthesis
D) Membrane factory for the cell
Question: What does the Golgi apparatus consist of?
A) A network of tubules
B) Stacks of flattened sacs called cisternae
C) A single large sac
D) A complex network of membranes
E) A series of vesicles
B) Stacks of flattened sacs called cisternae
Question: How are the cisternae of the Golgi apparatus different from those of the endoplasmic reticulum (ER)?
A) They are physically connected
B) They are larger in size
C) They contain ribosomes
D) They are not physically connected
E) They are involved in protein synthesis
D) They are not physically connected
Question: How is the structural directionality of a Golgi stack characterized?
A) The thickness of cisternae is uniform throughout the stack
B) Cisternae on opposite sides of the stack have similar molecular composition
C) Cisternae on opposite sides of the stack have differing thickness and molecular composition
D) The stack consists of only one type of cisterna
E) Cisternae in the middle of the stack are the thickest
C) Cisternae on opposite sides of the stack have differing thickness and molecular composition
Question: Where do vesicles from the endoplasmic reticulum (ER) fuse in the Golgi apparatus?
A) Cis face
B) Trans face
C) Middle region of the stack
D) Nucleus
E) ER lumen
A) Cis face
Question: Where do vesicles form and leave in the Golgi apparatus?
A) Cis face
B) Trans face
C) Middle region of the stack
D) Nucleus
E) ER lumen
B) Trans face
Question: How do secretory proteins depart from the endoplasmic reticulum (ER)?
A) They diffuse out of the ER membrane
B) They are transported by motor proteins
C) They are carried in vesicles called transport vesicles
D) They exit through nuclear pores
E) They are directly released into the cytosol
C) They are carried in vesicles called transport vesicles
Question: What is the purpose of different cisternae in the Golgi apparatus containing unique teams of enzymes?
A) To maintain structural integrity
B) To regulate temperature
C) To produce ATP
D) To manufacture and refine products in stages
E) To facilitate cell division
D) To manufacture and refine products in stages
Question: In which direction do the cisternae of the Golgi apparatus progress?
A) From trans face to cis face
B) From middle to trans face
C) They remain stationary
D) From cis face to trans face
E) They have no defined direction
D) From cis face to trans face
Question: How does the Golgi stack dispatch its products?
A) Through the nucleus
B) Through the ER
C) By releasing them directly into the cytosol
D) By budding vesicles from the trans face
E) By diffusing out of the Golgi membrane
D) By budding vesicles from the trans face
Question: How do molecular identification tags aid in sorting within the Golgi apparatus?
A) They alter the size of cisternae
B) They create structural directionality
C) They determine the thickness of cisternae
D) They act like postal codes on mailing labels
E) They are added to vesicles during fusion
D) They act like postal codes on mailing labels
Question: How do transport vesicles recognize their target membrane on the plasma membrane?
A) Through color recognition
B) By size matching
C) By directly fusing with it
D) By external molecules on their membranes recognizing “docking sites” on the plasma membrane
E) Through shape recognition
D) By external molecules on their membranes recognizing “docking sites” on the plasma membrane
Question: What is the primary function of a lysosome?
A) To produce ATP
B) To synthesize proteins
C) To store genetic information
D) To digest macromolecules through hydrolytic enzymes
E) To regulate cell division
D) To digest macromolecules through hydrolytic enzymes
Question: What is the primary function of a lysosome in a eukaryotic cell?
A) Energy production
B) DNA replication
C) Digesting (hydrolyzing) macromolecules
D) Photosynthesis
E) Carbohydrate synthesis
C) Digesting (hydrolyzing) macromolecules
Question: Under which pH environment do lysosomal enzymes work best?
A) Neutral pH
B) Alkaline pH
C) Acidic pH
D) Basic pH
E) Near-neutral pH
C) Acidic pH
Question: What process involves a lysosome fusing with a food vacuole to digest engulfed food particles?
A) Photosynthesis
B) Oxidative phosphorylation
C) Glycolysis
D) Phagocytosis
E) Translation
D) Phagocytosis
Question: What is the term for the process in which lysosomal enzymes break down the cell’s own organic material?
A) Autophagy
B) Phagocytosis
C) Oxidative phosphorylation
D) Translation
E) Endocytosis
A) Autophagy
Question: What happens during autophagy in a cell?
A) The cell consumes external nutrients
B) The lysosome leaks its contents
C) A damaged organelle becomes surrounded by a double membrane, and a lysosome fuses with the outer membrane of this vesicle, releasing small organic compounds to the cytosol
D) The nucleus replicates its DNA
E) The Golgi apparatus produces lysosomes
C) A damaged organelle becomes surrounded by a double membrane, and a lysosome fuses with the outer membrane of this vesicle, releasing small organic compounds to the cytosol
Question: What are vacuoles in a cell derived from?
A) Mitochondria
B) Nucleus
C) Ribosomes
D) Endoplasmic reticulum and Golgi apparatus
E) Lysosomes
D) Endoplasmic reticulum and Golgi apparatus
Question: What is the role of contractile vacuoles in maintaining cell homeostasis?
A) Digesting food particles
B) Producing energy
C) Maintaining an alkaline pH
D) Pumping excess water out of the cell to maintain ion and molecule concentration
E) Facilitating protein synthesis
D) Pumping excess water out of the cell to maintain ion and molecule concentration
Question: What is the main function of the central vacuole in mature plant cells?
A) Digesting macromolecules
B) Storing genetic information
C) Regulating pH
D) Maintaining cell shape
E) Being the main repository of inorganic ions
E) Being the main repository of inorganic ions
Question: What is the primary function of the cytoskeleton in a cell?
A) Energy production
B) DNA replication
C) Maintaining genetic material
D) Organizing structures and activities in the cell
E) Regulating pH
D) Organizing structures and activities in the cell
Question: How does the cytoskeleton contribute to maintaining the shape of animal cells?
A) By producing energy
B) By forming cell walls
C) By secreting enzymes
D) By giving mechanical support to the cell
E) By controlling gene expression
D) By giving mechanical support to the cell
Question: What characteristic of the cytoskeleton allows it to change the cell’s shape by dismantling and reassembling in different locations?
A) Rigidity
B) Non-dynamic behavior
C) Static structure
D) Dynamic nature
E) Resistance to change
D) Dynamic nature
Question: What is a common feature between the cytoskeleton in bacterial cells and eukaryotic cells?
A) The type of fibres they have
B) The proteins they are composed of
C) Their rigidity
D) Their lack of interaction with motor proteins
E) The presence of fibres forming a type of cytoskeleton
E) The presence of fibres forming a type of cytoskeleton
Question: What does the term “cell motility” encompass?
A) Only cell location changes
B) Only movements of cell parts
C) Both changes in cell location and movements of cell parts
D) Only cell division processes
E) Only interactions with the extracellular matrix
C) Both changes in cell location and movements of cell parts
Question: How do cytoskeletal elements and motor proteins contribute to cell movement?
A) They maintain genetic material
B) They form cell walls
C) They facilitate energy production
D) They allow whole cells to move along fibres outside the cell
E) They directly regulate gene expression
D) They allow whole cells to move along fibres outside the cell
Question: Which type of cytoskeletal element is the thickest?
A) Microtubules
B) Microfilaments
C) Intermediate filaments
D) Actin filaments
E) Keratin filaments
A) Microtubules
Question: What are microtubules constructed from?
A) Globular protein called actin
B) Globular protein called myosin
C) Globular protein called tubulin
D) Globular protein called keratin
E) Globular protein called collagen
C) Globular protein called tubulin
Question: What are the two slightly different polypeptides that make up a tubulin dimer?
A) Alpha-tubulin and gamma-tubulin
B) Alpha-tubulin and beta-tubulin
C) Beta-tubulin and delta-tubulin
D) Alpha-tubulin and epsilon-tubulin
E) Beta-tubulin and zeta-tubulin
B) Alpha-tubulin and beta-tubulin
Question: Which end of a microtubule can accumulate or release tubulin dimers at a higher rate during cellular activities?
A) Minus end
B) Plus end
C) Central end
D) Outer end
E) Middle end
B) Plus end
Question: What is one function of microtubules in the cell?
A) Energy production
B) Protein synthesis
C) Making phospholipids to build the membrane
D) Moving vesicles and organelles along their tracks
E) DNA replication
D) Moving vesicles and organelles along their tracks
Question: Where do microtubules often grow out from in a cell?
A) Mitochondria
B) Nucleus
C) Endoplasmic reticulum
D) Centrosome
E) Golgi apparatus
D) Centrosome
Question: What structural components are cilia and flagella primarily composed of?
A) Microfilaments
B) Intermediate filaments
C) Microtubules
D) Actin and myosin
E) Tubulin and kinesin
C) Microtubules
Question: How does the motion of a flagellum differ from that of cilia?
A) Flagellum has an undulating motion like the tail of a fish, while cilia work more like oars with alternating power and recovery strokes
B) Flagellum has a rotational motion, while cilia move in a straight line
C) Flagellum moves only in one direction, while cilia move in multiple directions
D) Flagellum moves by contracting and relaxing, while cilia move by expanding and contracting
E) They move in the same way
A) Flagellum has an undulating motion like the tail of a fish, while cilia work more like oars with alternating power and recovery strokes
Question: What are kinesins?
A) Motor proteins that move vesicles and organelles along microtubules
B) Building blocks of microtubules
C) Motor proteins that move vesicles and organelles along microfilaments
D) Structural proteins that give shape to the nucleus
E) Motor proteins that move vesicles and organelles along intermediate filaments
A) Motor proteins that move vesicles and organelles along microtubules
Question: What are microfilaments made of?
A) Keratin
B) Tubulin and kinesin
C) Actin and kinesin
D) Actin and microtubulin
E) Actin
E) Actin
Question: What motor protein is associated with microfilaments and involved in muscle contraction?
A) Kinesin
B) Dynein
C) Myosin
D) Tubulin
E) Actin
C) Myosin
Question: What is the most common type of intermediate filament in animal cells?
A) Actin
B) Tubulin
C) Myosin
D) Keratin
E) Collagen
D) Keratin
Question: What are the main ingredients of the extracellular matrix (ECM) in animal cells?
A) Proteins and lipids
B) Carbohydrates and nucleic acids
C) Amino acids and sugars
D) Glycoproteins and carbohydrate-containing molecules
E) DNA and RNA
D) Glycoproteins and carbohydrate-containing molecules
Question: How do integrins contribute to cellular interactions with the extracellular matrix?
A) By producing energy
B) By forming cytoskeletal elements
C) By facilitating carbohydrate synthesis
D) By connecting the extracellular matrix to the cell
E) By breaking down glycoproteins
D) By connecting the extracellular matrix to the cell
Question: What is the main function of tight junctions between cells?
A) Facilitating cellular respiration
B) Preventing movement of organelles between cells
C) Allowing direct exchange of cellular content
D) Preventing fluid movement across a layer of cells
E) Enhancing cell division
D) Preventing fluid movement across a layer of cells
Question: What is a characteristic of desmosomes?
A) They allow fluid movement between cells
B) They are cytoplasmic communicating channels
C) They are responsible for muscle contraction
D) They provide strong connections between cells
E) They only exist in plant cells
D) They provide strong connections between cells
Question: What is the main purpose of gap junctions?
A) Preventing direct physical contact between cells
B) Maintaining the structural integrity of the extracellular matrix
C) Forming strong connections between cells
D) Providing cytoplasmic communicating channels
E) Transporting large molecules between cells
D) Providing cytoplasmic communicating channels
Question: What is the primary function of ATP in cellular processes?
A) Storing genetic information
B) Building proteins
C) Catalyzing enzymatic reactions
D) Powering cellular work by coupling exergonic and endergonic reactions
E) Regulating membrane transport
D) Powering cellular work by coupling exergonic and endergonic reactions
Question: What are the components of ATP’s structure?
A) Ribose, adenine, and a single phosphate group
B) Glucose, thymine, and two phosphate groups
C) Deoxyribose, guanine, and a single phosphate group
D) Ribose, uracil, and two phosphate groups
E) Ribose, adenine, and a chain of three phosphate groups
E) Ribose, adenine, and a chain of three phosphate groups
Question: How is energy released from ATP?
A) By synthesis
B) By oxidation
C) By hydrolysis
D) By phosphorylation
E) By reduction
C) By hydrolysis
Question: How do cells utilize the energy released during ATP hydrolysis?
A) By storing it in the nucleus
B) By converting it into heat energy
C) By converting it into light
D) By harnessing it in various ways to perform cellular work
E) By transferring it to water molecules
D) By harnessing it in various ways to perform cellular work
Question: What effect does ATP hydrolysis have on proteins?
A) It causes changes in the shapes and binding affinities of proteins.
B) It causes proteins to denature.
C) It leads to protein synthesis.
D) It has no effect on proteins.
E) It decreases the stability of proteins.
A) It causes changes in the shapes and binding affinities of proteins.
Question: How is ATP regenerated within the cell?
A) By directly absorbing energy from the environment
B) By participating in photosynthesis reactions
C) By breaking down glucose molecules
D) By adding a phosphate group to ADP using energy from catabolic reactions
E) By releasing energy from water molecules
D) By adding a phosphate group to ADP using energy from catabolic reactions
Question: What is the role of enzymes in metabolic reactions?
A) Building macromolecules
B) Regulating gene expression
C) Lowering activation energy barriers and speeding up reactions
D) Forming cellular membranes
E) Producing ATP
C) Lowering activation energy barriers and speeding up reactions
Question: What is the term for the initial energy investment required to start a reaction?
A) Activation energy
B) Enzyme activity
C) Substrate energy
D) Hydrolysis energy
E) Exergonic energy
A) Activation energy
Question: What is the reactant that an enzyme acts on called?
A) Substrate
B) Catalytic agent
C) Product molecule
D) Metabolic intermediate
E) Molecule
A) Substrate
Question: What is the term for the specific region on an enzyme where the substrate binds and catalysis takes place?
A) Binding groove
B) Catalytic center
C) Pocket
D) Active site
E) Substrate hub
D) Active site
Question: What happens to an enzyme after the catalysis of its substrate?
A) It remains bound to the product
B) It is inactivated and degraded
C) It remains unchanged
D) It releases the product and is free to bind to another substrate molecule
E) It is denatured
D) It releases the product and is free to bind to another substrate molecule
Question: What is the main purpose of catabolic pathways in metabolism?
A) Synthesizing complex molecules
B) Storing energy in organic fuels
C) Releasing energy by breaking down complex molecules
D) Converting light energy into chemical energy
E) Facilitating cell division
B) Storing energy in organic fuels
Question: What is the process where the loss of electrons from one substance is called oxidation and the addition of electrons to another substance is called reduction?
A) Cellular respiration
B) Glycolysis
C) Photosynthesis
D) Redox reaction
E) Fermentation
D) Redox reaction
Question: Which metabolic pathway begins the degradation process by breaking glucose into two molecules of pyruvate?
A) Citric acid cycle
B) Electron transport chain
C) Fermentation
D) Glycolysis
E) Oxidative phosphorylation
D) Glycolysis
Question: In eukaryotes, what happens to pyruvate after it enters the mitochondrion?
A) It is immediately excreted from the cell
B) It is converted to glucose
C) It is converted to lactate
D) It is oxidized to acetyl CoA
E) It is oxidized to alcohol
D) It is oxidized to acetyl CoA
Question: What is another name for the citric acid cycle?
A) Electron transport chain
B) Glycolysis
C) Oxidative phosphorylation
D) Tricarboxylic acid cycle
E) Calvin cycle
D) Tricarboxylic acid cycle
Which process involves passing electrons from NADH to oxygen and accumulating protons across a membrane?
A) Glycolysis
B) Citric acid cycle
C) Autophagy phosphorylation
D) Electron transport chain
E) ATP synthesis
D) Electron transport chain
What is the main outcome of the electron transport chain (ETC) in mitochondria?
A) Synthesis of glucose
B) Release of CO2
C) Conversion of ATP to ADP
D) Accumulation of protons between mitochondrial membranes
E) Breakdown of NADH
D) Accumulation of protons between mitochondrial membranes
How does ATP synthase utilize an existing ion gradient?
A) Generates electron transport
B) Releases protons
C) Consumes oxygen
D) Converts NAD+ to NADH
E) Powers ATP synthesis
E) Powers ATP synthesis
What is the direct source of energy that drives ATP synthase in mitochondria?
A) Glucose breakdown
B) Pyruvate oxidation
C) Citric acid cycle
D) DNA replication
E) Difference in H+ concentration across the inner mitochondrial membrane
E) Difference in H+ concentration across the inner mitochondrial membrane
