Lecture 1 Flashcards

Quiz prep

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1
Q

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

A

The smallest unit capable of of independent life and forming all living organisms and body tissues

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2
Q

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

A

Between 1 and 100 μm in diameter

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3
Q

How do biologists examine cells?

A) With naked eyes

B) Through telescopes

C) Using sonar technology

D) By employing microscopes

E) Through chemical reactions

A

By employing microscopes

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4
Q

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

A

Visible light

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5
Q

What do fluorescent light microscopes capture?

A) Radio waves

B) Infrared light

C) Ultraviolet light

D) Fluorescence

E) Heat radiation

A

Fluorescence

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6
Q

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

A

Transmission electron microscopes and Scanning electron microscopes

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7
Q

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

A

The internal structure of thin sections of cells

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8
Q

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

A

Studying the fine details of cell surfaces

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9
Q

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

A

Polysaccharides (sugars), Lipids, Nucleic acids (DNA, RNA), and Proteins

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10
Q

What constitutes the majority of a cell’s composition?

A) Large molecules
B) Carbohydrates
C) Lipids
D) Water
E) Proteins

A

Water

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11
Q

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

A

Lipids or polymers

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12
Q

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

A

They are not composed of monomers

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13
Q

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

A

Their significant size on the molecular scale

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14
Q

What are macromolecules primarily made of?

A) Nucleotides
B) Amino acids
C) Monomers
D) Polymers
E) Hydrocarbons

A

Monomers

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15
Q

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

A long molecule made up of similar or identical building blocks linked by covalent bonds

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16
Q

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

A

Through dehydration reactions

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17
Q

What is the reverse process of dehydration called?

A) Condensation
B) Polymerization
C) Oxidation
D) Hydrolysis
E) Fusion

A

Hydrolysis

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18
Q

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

A

The addition of water to break covalent bonds

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19
Q

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

A

Serving as fuel and building material

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20
Q

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

A

D) Being some multiple of the unit CH2O

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21
Q

What linkage joins two monosaccharides to form a disaccharide?

A) Peptide linkage
B) Ionic linkage
C) Hydrogen bond
D) Glycosidic linkage
E) Ester linkage

A

Glycosidic linkage

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22
Q

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

A

Polymers with a few hundred to a few thousand monosaccharides joined by glycosidic linkages

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23
Q

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

A

As storage polysaccharides

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24
Q

What do animals store as a storage polysaccharide?

A) Starch
B) Cellulose
C) Amylopectin
D) Glycogen
E) Amylose

A

Glycogen

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25
Q

What do plants store as a storage polysaccharide?

A) Starch
B) Glycogen
C) Chitin
D) Cellulose
E) Collagen

A

Starch

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26
Q

What purpose do structural polysaccharides serve in organisms?

A) Energy storage
B) Enzyme activation
C) Building strong materials
D) DNA replication
E) Cellular respiration

A

Building strong materials

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27
Q

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

A

D) They give the two molecules distinct three-dimensional shapes

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28
Q

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

A

D) Diversity and hydrophobic nature

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29
Q

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

A

Because they share a hydrophobic nature and mix poorly with water

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30
Q

What components do lipids primarily constitute?

A) DNA and RNA
B) Carbohydrates
C) Cellulose
D) Cell membranes
E) Polypeptides

A

Cell membranes

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31
Q

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

A

Fats, phospholipids, and steroids

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32
Q

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

A

Glycerol and fatty acids

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33
Q

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

A glycerol molecule joined to three fatty acid molecules

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34
Q

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

A

Phospholipids have two fatty acids and a phosphate group

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35
Q

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

A

The structure of the hydrocarbon chains of the fatty acids

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36
Q

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

A hydrophilic (polar) head and two hydrophobic (nonpolar) tails

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37
Q

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

A

They are major constituents of cell membranes

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38
Q

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

A carbon skeleton consisting of four fused rings

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39
Q

What are proteins composed of?
A) Amino acids
B) Monosaccharides
C) Nucleotides
D) Fatty acids
E) Glycerol and phosphate groups

A

Amino acids

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40
Q

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

A variety of structures resulting in a wide range of functions

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41
Q

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

A

They mediate and regulate most cellular activities

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42
Q

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%

A

Over 50%

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43
Q

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

A

Accelerating specific chemical reactions

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44
Q

What are antibodies?
A) Carbohydrates
B) Lipids
C) Nucleic acids
D) Proteins
E) Hormones

A

Proteins

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45
Q

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

A

Serving as a source of amino acids

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46
Q

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

A

Mediating the selective transport of substances

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47
Q

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

A

It has both an amino group and a carboxyl group

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48
Q

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

A

They all have both amino and carboxyl groups

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49
Q

How many different amino acids makeup proteins?
A) 10
B) 15
C) 20
D) 25
E) 30

A

20

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50
Q

What is the fundamental building block of proteins?
A) Carbohydrates
B) Fatty acids
C) Monosaccharides
D) Amino acids
E) Nucleotides

A

Amino acids

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51
Q

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

A

Hydrogen bond

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52
Q

How many levels of protein structure are there?
A) Two
B) Three
C) Four
D) Five
E) Six

A

Four

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53
Q

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

A

Sequence of amino acids

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54
Q

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

A

Hydrogen bonds

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55
Q

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

A

Both alpha helices and beta-strands

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56
Q

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

A

Overall shape resulting from interactions between amino acids

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57
Q

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

A

The aggregation of two or more polypeptide chains

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58
Q

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

A

Storing, transmitting, and expressing hereditary information

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59
Q

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

A

Deoxyribonucleic acid (DNA) and ribonucleic acid (RNA)

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60
Q

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

A

DNA → RNA → Protein

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61
Q

Where is genetic information stored in a eukaryotic cell?
A) Nucleus
B) Cytoplasm
C) Mitochondria
D) Chloroplasts
E) Nucleus, mitochondria, and chloroplasts

A

Nucleus

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62
Q

What are the monomers of nucleic acids called?
A) Amino acids
B) Nucleotides
C) Monosaccharides
D) Peptides
E) Polynucleotides

A

Nucleotides

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63
Q

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

A nitrogenous base, a five-carbon sugar, and one phosphate group

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64
Q

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

A

Antiparallel arrangement

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65
Q

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

A

In opposite 5’ → 3’ directions

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66
Q

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

A

Between stretches of nucleotides in the same RNA molecule

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67
Q

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)

A

Adenine (A) with thymine (T), and guanine (G) with cytosine (C)

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68
Q

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

A

Eukaryotic cells have a true nucleus and internal membranes

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69
Q

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

A

In a region called the nucleoid

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70
Q

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

A

In an organelle called the nucleus

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71
Q

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

A

Cytoplasm

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72
Q

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

A combination of lipids and proteins

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73
Q

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

A

Both hydrophilic and hydrophobic parts are inside the membrane

74
Q

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

A

Carbohydrate side chains

75
Q

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

A

Amphipathic molecule

76
Q

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

A fluid bilayer of phospholipids with embedded protein molecules

77
Q

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

A

In the nucleus

78
Q

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

A

They carry out protein synthesis

79
Q

What process occurs in the nucleus?
A) Protein synthesis
B) Energy production
C) Photosynthesis
D) Transcription
E) Translation

A

Transcription

80
Q

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

A

In the ribosomes

81
Q

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

A

To separate the nucleus from the cytoplasm

82
Q

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

A

It is composed of two membranes

83
Q

What structures regulate the entry and exit of molecules from the nucleus?
A) Nuclear pores
B) Ribosomes
C) Nucleoli
D) Lysosomes
E) Endoplasmic reticulum

A

Nuclear pores

84
Q

What is the nucleolus responsible for synthesizing?
A) DNA molecules
B) Messenger RNA (mRNA)
C) Transfer RNA (tRNA)
D) Ribosomal RNA (rRNA)
E) Proteins

A

Ribosomal RNA (rRNA)

85
Q

What cellular components are responsible for protein synthesis?
A) Nucleoli
B) Nuclei
C) Mitochondria
D) Ribosomes
E) Lysosomes

A

Ribosomes

86
Q

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

A

Large and Small subunits

87
Q

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

A

Both in the cytosol and attached to the endoplasmic reticulum or nuclear envelope

88
Q

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

A

No, they are structurally identical

89
Q

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

A

Proteins that function within the cytosol

90
Q

What is the main function of mitochondria?
A) Protein synthesis
B) Photosynthesis
C) Cellular respiration
D) Lipid synthesis
E) DNA replication

A

Cellular respiration

91
Q

What is the role of chloroplasts in plants and algae?
A) Cellular respiration
B) Protein synthesis
C) Photosynthesis
D) ATP synthesis
E) Lipid metabolism

A

Photosynthesis

92
Q

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

A

To provide a barrier for compartmentalization and energy conversion

93
Q

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

A

Extracting energy from sugars, fats, and other fuels

94
Q

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

A

Ribosomes

95
Q

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

A

An early ancestor of eukaryotic cells engulfed a non-photosynthetic prokaryotic cell and established an endosymbiotic relationship

96
Q

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

A

Oxygen-using, non-photosynthetic prokaryotes

97
Q

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

A

Convex with infoldings called cristae

98
Q

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

A

Both mitochondrial DNA and ribosomes

99
Q

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

A

They fuse, divide, and are very dynamic

100
Q

What is the primary role of chloroplasts?
A) ATP synthesis
B) Cellular respiration
C) Photosynthetic production of sugar
D) Protein synthesis
E) DNA replication

A

Photosynthetic production of sugar

101
Q

What term is used to describe colorless organelles that store starch?
A) Chromoplast
B) Leucoplast
C) Chloroplast
D) Amyloplast
E) Peroxisome

A

Amyloplast

102
Q

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

A

Chlorophyll pigment and enzymes for photosynthetic sugar production

103
Q

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

A

To break down fatty acids

104
Q

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

A

C) Regulating protein traffic and performing metabolic functions

105
Q

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

A

D) Nuclear envelope, endoplasmic reticulum, Golgi apparatus, lysosomes, vesicles, vacuoles, and plasma membrane

106
Q

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

A

D) They are related either through direct physical continuity or by the transfer of membrane segments as tiny vesicles

107
Q

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

A) Membranous tubules and sacs called cisternae

108
Q

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

A

B) Smooth ER lacks ribosomes, while rough ER has them

109
Q

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

A

D) Protein synthesis

110
Q

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

A

D) Both in the cytosol and attached to the endoplasmic reticulum or nuclear envelope

111
Q

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

A) Yes

112
Q

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

A

D) Synthesis of lipids, metabolism of carbohydrates, detoxification of drugs, and storage of calcium ions

113
Q

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

A

B) Membrane proteins and secreted proteins

114
Q

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

A

E) Lumen of the ER

115
Q

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

A

C) They are carried in vesicles called transport vesicles

116
Q

Question: What are most secretory proteins covalently bonded to?
A) Lipids
B) Nucleic acids
C) Carbohydrates
D) Amino acids
E) Peptides

A

C) Carbohydrates

117
Q

Question: Where are carbohydrates attached to proteins in the endoplasmic reticulum (ER)?
A) Cytosol
B) Nucleus
C) Golgi apparatus
D) Mitochondria
E) ER lumen

A

E) ER lumen

118
Q

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

A

D) Membrane factory for the cell

119
Q

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

A

B) Stacks of flattened sacs called cisternae

120
Q

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

A

D) They are not physically connected

121
Q

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

A

C) Cisternae on opposite sides of the stack have differing thickness and molecular composition

122
Q

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

A) Cis face

123
Q

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

A

B) Trans face

124
Q

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

A

C) They are carried in vesicles called transport vesicles

125
Q

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

A

D) To manufacture and refine products in stages

126
Q

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

A

D) From cis face to trans face

127
Q

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

A

D) By budding vesicles from the trans face

128
Q

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

A

D) They act like postal codes on mailing labels

129
Q

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

A

D) By external molecules on their membranes recognizing “docking sites” on the plasma membrane

130
Q

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

A

D) To digest macromolecules through hydrolytic enzymes

131
Q

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

A

C) Digesting (hydrolyzing) macromolecules

132
Q

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

A

C) Acidic pH

133
Q

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

A

D) Phagocytosis

134
Q

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

A) Autophagy

135
Q

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

A

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

136
Q

Question: What are vacuoles in a cell derived from?
A) Mitochondria
B) Nucleus
C) Ribosomes
D) Endoplasmic reticulum and Golgi apparatus
E) Lysosomes

A

D) Endoplasmic reticulum and Golgi apparatus

137
Q

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

A

D) Pumping excess water out of the cell to maintain ion and molecule concentration

138
Q

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

A

E) Being the main repository of inorganic ions

139
Q

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

A

D) Organizing structures and activities in the cell

140
Q

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

A

D) By giving mechanical support to the cell

141
Q

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

A

D) Dynamic nature

142
Q

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

A

E) The presence of fibres forming a type of cytoskeleton

143
Q

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

A

C) Both changes in cell location and movements of cell parts

144
Q

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

A

D) They allow whole cells to move along fibres outside the cell

145
Q

Question: Which type of cytoskeletal element is the thickest?
A) Microtubules
B) Microfilaments
C) Intermediate filaments
D) Actin filaments
E) Keratin filaments

A

A) Microtubules

146
Q

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

A

C) Globular protein called tubulin

147
Q

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

A

B) Alpha-tubulin and beta-tubulin

148
Q

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

A

B) Plus end

149
Q

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

A

D) Moving vesicles and organelles along their tracks

150
Q

Question: Where do microtubules often grow out from in a cell?
A) Mitochondria
B) Nucleus
C) Endoplasmic reticulum
D) Centrosome
E) Golgi apparatus

A

D) Centrosome

151
Q

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

A

C) Microtubules

152
Q

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

A) Flagellum has an undulating motion like the tail of a fish, while cilia work more like oars with alternating power and recovery strokes

153
Q

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

A) Motor proteins that move vesicles and organelles along microtubules

154
Q

Question: What are microfilaments made of?
A) Keratin
B) Tubulin and kinesin
C) Actin and kinesin
D) Actin and microtubulin
E) Actin

A

E) Actin

155
Q

Question: What motor protein is associated with microfilaments and involved in muscle contraction?
A) Kinesin
B) Dynein
C) Myosin
D) Tubulin
E) Actin

A

C) Myosin

156
Q

Question: What is the most common type of intermediate filament in animal cells?
A) Actin
B) Tubulin
C) Myosin
D) Keratin
E) Collagen

A

D) Keratin

157
Q

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

A

D) Glycoproteins and carbohydrate-containing molecules

158
Q

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

A

D) By connecting the extracellular matrix to the cell

159
Q

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

A

D) Preventing fluid movement across a layer of cells

160
Q

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

A

D) They provide strong connections between cells

161
Q

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

A

D) Providing cytoplasmic communicating channels

162
Q

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

A

D) Powering cellular work by coupling exergonic and endergonic reactions

163
Q

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

A

E) Ribose, adenine, and a chain of three phosphate groups

164
Q

Question: How is energy released from ATP?
A) By synthesis
B) By oxidation
C) By hydrolysis
D) By phosphorylation
E) By reduction

A

C) By hydrolysis

165
Q

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

A

D) By harnessing it in various ways to perform cellular work

166
Q

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

A) It causes changes in the shapes and binding affinities of proteins.

167
Q

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

A

D) By adding a phosphate group to ADP using energy from catabolic reactions

168
Q

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

A

C) Lowering activation energy barriers and speeding up reactions

169
Q

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

A) Activation energy

170
Q

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

A) Substrate

171
Q

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

A

D) Active site

172
Q

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

A

D) It releases the product and is free to bind to another substrate molecule

173
Q

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

A

B) Storing energy in organic fuels

174
Q

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

A

D) Redox reaction

175
Q

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

A

D) Glycolysis

176
Q

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

A

D) It is oxidized to acetyl CoA

177
Q

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

A

D) Tricarboxylic acid cycle

178
Q

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

A

D) Electron transport chain

179
Q

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

A

D) Accumulation of protons between mitochondrial membranes

180
Q

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

A

E) Powers ATP synthesis

181
Q

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

A

E) Difference in H+ concentration across the inner mitochondrial membrane