Lecture 2 - Cells: The living units Flashcards
How are cells diverse?
Types differ in size, shape, and subcellular components; these differences lead to differences in functions
Which of the following is NOT a basic part of a human cell?
A) Plasma membrane
B) Cytoplasm
C) Mitochondria
D) Nucleus
Answer: C (Mitochondria is an organelle, not a basic part of the cell structure)
The principle that the structure and function of a cell are complementary is called:
A) Biochemical Function
B) Generalized Cell Theory
C) Structure-Function Complementarity
D) Homeostasis
Answer: C
Heat and visible light are most associated with which form of energy?
electrical energy
chemical energy
mechanical energy
radiant energy
none of the above
radiant energy
Starch is:
Question 2 options:
a monosaccharide used by plants as fuel source
a fatty acid used by plants as a fuel source
a polymer of amino acids used by animals as a fuel source
a stored form of carbohydrate used by plants
none of the above
a stored form of carbohydrate used by plants - specifically polysachrides
Which of the following is incorrect regarding carbohydrates, lipids, proteins and nucleic acids?
they are all considered organic compounds
they are all essential foundations of life
they all contain carbon
they all form polymers by binding to glycerol
they all form polymers by binding to glycerol
Which of the following bonds demonstrates electronegativity due to an unequal sharing of electrons between two atoms?
the bonds between sodium and chloride in a salt crystal
the bonds between oxygen and hydrogen within a water molecule
the bonds between oxygen and hydrogen that allow two water molecules to join
the bonds between oxygen and carbon in a carbon dioxide molecule
none of the above
Answer: the bonds between oxygen and hydrogen within a water molecule
Unlike triglycerides, phospholipids:
do not contain fatty acids
do not contain glycerol
do not contain carbons bound to hydrogens
have portions that are polar
none of the above
Answer: have portions that are polar
Which of the following does NOT belong in a molecule of DNA?
pentose
phosphorus
nitrogen
purines
purines
The passage of a fatty acid through a cell membrane is an example of:
facilitated diffusion
active transport
carrier-mediated facilitated diffusion
osmosis
none of the above
Answer: none of the above
its simple diffusion
Proteins can be:
classified as integral
receptors
channels
enzymes
all of the above
all of the above
The sodium-potassium pump is an example of a symporter that promotes primary active transport.
True False
False
The sodium-potassium pump is an antiporter (not a symporter) because it transports sodium (Na⁺) out of the cell and potassium (K⁺) into the cell, in opposite directions. It is, however, an example of primary active transport, as it uses ATP directly to function.
A solution that can cause cell lysis by driving water into a cell is:
hypotonic
isotonic
hypertonic
hyperosmotic
hypotonic
The act of bringing fluid into a cell is most associated with:
phagocytosis
receptor-mediated endocytosis
pinocytosis
exocytosis
none of the above
Answer: Pinocytosis
Assuming normal resting membrane potential of a cell, if potassium were to leak down its concentration gradient, the result would be:
the inside of the cell would become more negative
potassium would leave the cell
the inside of the cell would become more positive
potassium would enter the cell
A and B
C and D
A and B
New transport vesicles pinch off of the trans face of:
the smooth ER
the rough ER
the Golgi apparatus
the lysosome
none of the above
the Golgi apparatus
plasma membrane proteins and phospholipids are synthesized:
in the rough endoplasmic reticulum
in the smooth endoplasmic reticulum
in the Golgi apparatus
in the peroxisome
in the rough endoplasmic reticulum
If a cell has a resting membrane potential (RMP) of -90 mV, the opening of a sodium channel can bring the RMP to:
Question 15 options:
-70 mV
-100 mV
-180 mV
-200 mV
none of the above
Answer: -70 mV
How many different types of human cells are estimated to exist?
A) 100
B) 250
C) 500
D) Over 250
Answer: D) Over 250
Which of the following best describes the plasma membrane?
A) A rigid structure that provides support
B) A flexible outer boundary that acts as a barrier
C) A solid layer preventing any movement of substances
D) None of the above
Answer: B) A flexible outer boundary that acts as a barrier
What is the term used to describe the unique pattern formed by membrane proteins and lipids in the plasma membrane?
A) Fluid mosaic model
B) Rigid structure model
C) Semi-permeable model
D) Lipid bilayer model
Answer: A) Fluid mosaic model
Which type of membrane protein is primarily involved in cell-to-cell recognition?
A) Integral proteins
B) Peripheral proteins
C) Glycoproteins
D) Lipids
Answer: C) Glycoproteins
What type of transport involves the movement of molecules down their concentration gradient without the use of ATP?
A) Active transport
B) Passive transport
C) Vesicular transport
D) Facilitated diffusion
Answer: B) Passive transport
Which of the following describes a hypertonic solution?
A) Has a lower osmolarity than the inside of the cell
B) Causes water to enter the cell
C) Has the same osmolarity as the inside of the cell
D) Has a higher osmolarity than the inside of the cell
Answer: D) Has a higher osmolarity than the inside of the cell
What is the primary function of the sodium-potassium pump?
A) To transport glucose into the cell
B) To maintain the resting membrane potential
C) To facilitate the uptake of oxygen
D) To remove waste from the cell
Answer: B) To maintain the resting membrane potential
Which organelle is primarily responsible for ATP production?
A) Ribosome
B) Nucleus
C) Mitochondria
D) Golgi apparatus
Answer: C) Mitochondria
What type of endocytosis is referred to as “cell eating”?
A) Pinocytosis
B) Receptor-mediated endocytosis
C) Phagocytosis
D) Exocytosis
Answer: C) Phagocytosis
Which component of the cytoplasm contains the cell’s organelles?
A) Cytosol
B) Inclusions
C) Cytoplasmic matrix
D) Cytoplasmic organelles
Answer: A) Cytosol
True or False: The plasma membrane is a static structure and does not change shape.
Answer: False (The plasma membrane is dynamic and has a fluid mosaic structure.)
True or False: Active transport processes do not require energy.
Answer: False (Active transport requires energy, usually in the form of ATP.)
True or False: Osmosis specifically refers to the movement of solutes across a selectively permeable membrane.
Answer: False (Osmosis refers to the movement of water across a selectively permeable membrane.)
True or False: The rough endoplasmic reticulum is studded with ribosomes and is involved in protein synthesis.
Answer: True
True or False: The lysosomes are responsible for detoxifying harmful substances within the cell.
Answer: False (Lysosomes contain digestive enzymes for breaking down waste; peroxisomes detoxify harmful substances.)
True or False: The nuclear envelope consists of a single membrane barrier.
Answer: False (The nuclear envelope consists of a double-membrane barrier.)
True or False: Glycocalyx is composed of proteins and is found on the surface of the plasma membrane.
Answer: False (Glycocalyx consists of sugars (carbohydrates) sticking out of the cell surface.)
True or False: Membrane potential is generated by the separation of charged particles across the plasma membrane.
Answer: True
True or False: Secondary active transport directly uses ATP to transport substances across the plasma membrane.
Answer: False (Secondary active transport relies on the ion gradients established by primary active transport.)
True or False: Ribosomes are the site of lipid synthesis in the cell.
Answer: False (Ribosomes are the site of protein synthesis.)
What are the three basic parts of human cells?
A) Cytoplasm, Cell wall, Nucleus
B) Plasma Membrane, Cytoplasm, Nucleus
C) Endoplasmic Reticulum, Golgi Apparatus, Mitochondria
D) Ribosomes, Lysosomes, Cytoskeleton
Answer: B) Plasma Membrane, Cytoplasm, Nucleus
Which type of membrane protein spans the entire membrane and has hydrophobic and hydrophilic regions?
A) Peripheral proteins
B) Integral proteins
C) Glycoproteins
D) Cholesterol
Answer: B) Integral proteins
Which structure is responsible for modifying, concentrating, and packaging proteins and lipids from the rough ER?
A) Ribosomes
B) Golgi apparatus
C) Mitochondria
D) Lysosomes
Answer: B) Golgi apparatus
What type of solution causes a cell to swell due to water entering?
A) Isotonic solution
B) Hypotonic solution
C) Hypertonic solution
D) Saturated solution
Answer: B) Hypotonic solution
Which organelle contains powerful detoxifying enzymes and is involved in breaking down fatty acids?
A) Mitochondria
B) Peroxisomes
C) Golgi apparatus
D) Endoplasmic reticulum
Answer: B) Peroxisomes
What is the primary role of the smooth endoplasmic reticulum?
A) Protein synthesis
B) Lipid metabolism and detoxification
C) Energy production
D) Digestion of cellular debris
Answer: B) Lipid metabolism and detoxification
Which of the following correctly describes primary active transport?
A) It moves substances down their concentration gradient.
B) It directly uses ATP to pump solutes across the membrane.
C) It involves vesicular transport.
D) It does not require any energy.
Answer: B) It directly uses ATP to pump solutes across the membrane.
The ‘resting membrane potential’ (RMP) is primarily influenced by the concentration of which ion?
A) Na+
B) Ca²+
C) K+
D) Cl-
Answer: C) K+
What type of signaling occurs when a ligand binds to a receptor and triggers a cascade of cellular responses?
A) Contact signaling
B) Chemical signaling
C) Electrical signaling
D) Mechanical signaling
Answer: B) Chemical signaling
What structure is referred to as the ‘cell’s internal framework’?
A) Cytoplasm
B) Cytoskeleton
C) Plasma membrane
D) Nucleus
Answer: B) Cytoskeleton
True or False: The cytoplasm is composed only of the cytosol.
Answer: False (The cytoplasm consists of cytosol, inclusions, and organelles.)
True or False: Facilitated diffusion requires energy to transport molecules across the plasma membrane.
Answer: False (Facilitated diffusion does not require energy; it relies on concentration gradients.)
True or False: Glycolipids contribute to the cell’s ability to recognize other cells.
Answer: True
True or False: The nucleus is responsible for producing ATP for the cell.
Answer: False (The mitochondria are responsible for ATP production.)
True or False: All cells have the same structure and function.
Answer: False (Different types of cells have variations in structure and function.)
True or False: Exocytosis is the process of transporting materials out of the cell.
Answer: True
True or False: Cholesterol is found in the plasma membrane and increases its fluidity.
Answer: False (Cholesterol increases the stability of the membrane, making it less fluid.)
True or False: Receptor-mediated endocytosis is a non-selective process.
Answer: False (Receptor-mediated endocytosis is selective as it depends on the binding of substances to specific receptors.)
True or False: The term ‘tonicity’ refers to the osmotic pressure of a solution relative to the cell.
Answer: True
True or False: The cytoskeleton consists only of microfilaments.
Answer: False (The cytoskeleton consists of microfilaments, intermediate filaments, and microtubules.)
What is the primary function of lysosomes? a) Protein synthesis
b) ATP production
c) Digestion of waste materials and cellular debris
d) Synthesis of lipids
Answer: c) Digestion of waste materials and cellular debris
What type of endocytosis involves the engulfing of large particles or cells? a) Pinocytosis
b) Phagocytosis
c) Receptor-mediated endocytosis
d) Exocytosis
Answer: b) Phagocytosis
Which of the following is NOT a function of the smooth endoplasmic reticulum? a) Lipid metabolism
b) Detoxification of drugs
c) Protein synthesis
d) Storage and release of calcium
Answer: c) Protein synthesis
The cytoskeleton is primarily made up of which of the following components? a) Glycolipids and phospholipids
b) Microfilaments, intermediate filaments, and microtubules
c) Ribosomal RNA and proteins
d) Vesicles and lysosomes
Answer: b) Microfilaments, intermediate filaments, and microtubules
What is the primary role of the Golgi apparatus in the cell? a) Synthesis of lipids
b) Modifying, concentrating, and packaging proteins
c) ATP production
d) Detoxification of harmful substances
Answer: b) Modifying, concentrating, and packaging proteins
What component of the glycocalyx plays a crucial role in cell recognition? a) Lipids
b) Proteins
c) Carbohydrates
d) Nucleic acids
Answer: c) Carbohydrates
In receptor-mediated endocytosis, what must occur for the substance to be pulled into the cell? a) The substance must diffuse through the lipid bilayer.
b) The substance must bind to its unique receptor on the cell surface.
c) The substance must undergo phagocytosis.
d) The substance must activate the smooth endoplasmic reticulum.
Answer: b) The substance must bind to its unique receptor on the cell surface.
True or False: The primary function of ribosomes is to synthesize ATP.
Answer: False
True or False: The membrane potential is primarily determined by the movement of sodium (Na+) and potassium (K+) ions across the plasma membrane.
Answer: True
True or False: Phagocytosis is a form of endocytosis that is specific to fluid uptake.
Answer: False
True or False: The Golgi apparatus modifies and packages proteins for secretion from the cell.
Answer: True
True or False: The cytoplasm includes the cytosol, organelles, and inclusions.
Answer: True
True or False: Integral proteins are loosely attached to the plasma membrane.
Answer: False
True or False: The primary role of peroxisomes is to detoxify harmful substances.
Answer: True
