Cellular Metabolism and Cells Flashcards
A molecule of fat consists of ___ and fatty acids.
A) Amino acids
B) Glucose
C) Glycerol
D) Guanine
C) Glycerol
Adenosine triphosphate (ATP) is an important molecule because it ________.
A) Is the result of catabolism
B) Releases energy in uncontrolled bursts
C) Stores energy for use by body cells
D) All of the above
C) Stores energy for use by body cells
A phospholipid ________.
A) Has both polar and nonpolar regions
B) Is made up of a triglyceride bonded to a phosphate group
C) Is a building block of ATP
D) Can donate both cations and anions in solution
A) Has both polar and nonpolar regions
Which type of lipid is always partially hydrophilic?
A) Steroids
B) Phospholipid
C) Polypeptide
D) Triglycerides
B) Phospholipid
Phospholipids are amphipathic—both hydrophilic and hydrophobic. Their hydrophobic regions are larger than their hydrophilic regions, though.
Define a hydrophilic molecule
A hydrophilic molecule (or region of a molecule) is one that is attracted to water.
Define a hydrophobic molecule
A hydrophobic molecule (or region of a molecule) repels and is repelled by water.
Define a amphipathic molecule
An amphipathic molecule is one that contains both a hydrophilic and a hydrophobic region.
Define Intracellular fluid (ICF)
Intracellular fluid (ICF) is the fluid interior of the cell.
Define Extracellular fluid (ECF)
Extracellular fluid (ECF) is the fluid environment outside the enclosure of the cell membrane.
Define Interstitial fluid (IF)
Interstitial fluid (IF) is the term given to extracellular fluid not contained within blood vessels.
What is integral protein?
An integral protein is a protein that is embedded in the membrane.
What is a channel protein?
A channel protein is an example of an integral protein that selectively allows particular materials, such as certain ions, to pass into or out of the cell.
What is a receptor?
A receptor is a type of recognition protein that can selectively bind a specific molecule outside the cell, and this binding induces a chemical reaction within the cell.
What is a ligand?
A ligand is the specific molecule that binds to and activates a receptor.
What is a glycoprotein?
A glycoprotein is a protein that has carbohydrate molecules attached, which extend into the extracellular matrix.
What is a glycocalyx?
The glycocalyx is a fuzzy-appearing coating around the cell formed from glycoproteins and other carbohydrates attached to the cell membrane.
What are peripheral proteins?
Peripheral proteins are typically found on the inner or outer surface of the lipid bilayer but can also be attached to the internal or external surface of an integral protein.
What does it mean when a membrane has selective permeability?
A membrane that has selective permeability allows only substances meeting certain criteria to pass through it unaided.
What is passive transport?
Passive transport is the movement of substances across the membrane without the expenditure of cellular energy.
What is active transport?
Active transport is the movement of substances across the membrane using energy from adenosine triphosphate (ATP).
What is a concentration gradient?
A concentration gradient is the difference in concentration of a substance across a space. Molecules
Define diffusion
Diffusion is the movement of particles from an area of higher concentration to an area of lower concentration.
What is facilitated diffusion?
Facilitated diffusion is the diffusion process used for those substances that cannot cross the lipid bilayer due to their size, charge, and/or polarity
Define osmosis
Osmosis is the diffusion of water through a semipermeable membrane
What does it mean when something is isotonic?
Two solutions that have the same concentration of solutes are said to be isotonic (equal tension).
What does it mean when something is hypertonic?
A solution that has a higher concentration of solutes than another solution is said to be hypertonic, and water molecules tend to diffuse into a hypertonic solution
What does it mean when something is hypotonic?
Cells in a hypertonic solution will shrivel as water leaves the cell via osmosis. In contrast, a solution that has a lower concentration of solutes than another solution is said to be hypotonic, and water molecules tend to diffuse out of a hypotonic solution.
What is the sodium potassium pump?
The sodium-potassium pump, which is also called Na+/K+ ATPase, transports sodium out of a cell while moving potassium into the cell.
What is an electrical gradient?
An electrical gradient is a difference in electrical charge across a space.
Define endocytosis
Endocytosis (bringing “into the cell”) is the process of a cell ingesting material by enveloping it in a portion of its cell membrane, and then pinching off that portion of membrane
Define vesicle
A vesicle is a membranous sac—a spherical and hollow organelle bounded by a lipid bilayer membrane.
Define phagocytosis
Phagocytosis (“cell eating”) is the endocytosis of large particles.
Define pinocytosis
In contrast to phagocytosis, pinocytosis (“cell drinking”) brings fluid containing dissolved substances into a cell through membrane vesicles.
What is receptor-mediated endocytosis?
Receptor-mediated endocytosis is endocytosis by a portion of the cell membrane that contains many receptors that are specific for a certain substance.
Define exocytosis
In contrast with endocytosis, exocytosis (taking “out of the cell”) is the process of a cell exporting material using vesicular transport
Because they are embedded within the membrane, ion channels are examples of ________.
A) Receptor proteins
B) Integral proteins
C) Peripheral proteins
D) Glycoproteins
B) Integral proteins
To form a bilayer within the plasma membrane, the hydrophilic heads interact with ________ while the hydrophobic tails interact with ________.
A) Intra- and Extracellular fluid; each other
B) Extracellular fluid; Intracellular fluid
C) Proteins; Carbohydrates
D) Each other; Intra- and Extracellular fluid
A) Intra- and Extracellular fluid; each other
Placing a cell into a hypotonic solution will cause water to:
A) Leave the cell
B) Enter the cell
C) Flow against its concentration gradient
D) Enter the cell and leave the cell at the same rate
B) Enter the cell
A macrophage is a type of immune cell that is responsible for detecting, engulfing and destroying pathogens found roaming around the body. Which vesicular transport mechanism would a macrophage use to accomplish its task?
A) Receptor-mediated endocytosis
B) Pinocytosis
C) Phagocytosis
D) Exocytosis
C) Phagocytosis
________ transport uses energy to move a substance across the cell membrane, while ________ transport does not use energy from the cell.
A) Passive, active
B) Active, endocytosis
C) Active; passive
C) Active; passive
Which of the following is a functional group that is part of a building block of proteins?
A) Phosphate
B) Adenine
C) Amino
D) Hydroxyl
C) Amino
Which type of molecule makes up the majority of the cell membrane?
A) Cholesterol
B) Membrane proteins
C) Phospholipids
D) Glycolipids
C) Phospholipids
Define Cytosol
Cytosol, the jelly-like substance within the cell, provides the fluid medium necessary for biochemical reactions.
What is an organelle?
An organelle (“little organ”) is one of several different types of membrane-enclosed bodies in the cell, each performing a unique function.
What composes the cytoplasm?
The organelles and cytosol, taken together, compose the cell’s cytoplasm.
What is the nucleus?
The nucleus is a cell’s central organelle, which contains the cell’s DNA
What is the endoplasmic reticulum (ER)?
The endoplasmic reticulum (ER) is a system of channels that is continuous with the nuclear membrane (or “envelope”) covering the nucleus and composed of the same lipid bilayer material.
Define ribosome
A ribosome is an organelle that serves as the site of protein synthesis.
What is the Golgi apparatus?
The Golgi apparatus is responsible for sorting, modifying, and shipping off the products that come from the rough ER, much like a post-office.
What is the lysosome?
A lysosome is an organelle that contains enzymes that break down and digest unneeded cellular components, such as a damaged organelle.
Define Autophagy
Autophagy (“self-eating”) is the process of a cell digesting its own structures.
Define autolysis
This “self-destruct” mechanism is called autolysis, and makes the process of cell death controlled (a mechanism called “apoptosis”).
What is the mitochondrion?
A mitochondrion (plural = mitochondria) is a membranous, bean-shaped organelle that is the “energy transformer” of the cell.
What is a peroxisome?
Like lysosomes, a peroxisome is a membrane-bound cellular organelle that contains mostly enzymes
What is Reactive oxygen species (ROS)?
Reactive oxygen species (ROS) such as peroxides and free radicals are the highly reactive products of many normal cellular processes, including the mitochondrial reactions that produce ATP and oxygen metabolism.
What is an example of Reactive oxygen species (ROS)?
Examples of ROS include the hydroxyl radical OH, H2O2, and superoxide ( O−2)
What is a mutation?
A mutation is a change in the nucleotide sequence in a gene within a cell’s DNA, potentially altering the protein coded by that gene.
What is the cytoskeleton?
The cytoskeleton is a group of fibrous proteins that provide structural support for cells, but this is only one of the functions of the cytoskeleton.
What is a microtubule?
The thickest of the three is the microtubule, a structural filament composed of subunits of a protein called tubulin.
What are the three kinds of protein based filaments that make the complex threadlike network thought the body of the cell?
Microfilaments, intermediate filaments, and microtubules
Microtubules also make up two types of cellular appendages important for motion. What are they?
Cilia and flagella
What is cilia?
Cilia are found on many cells of the body, including the epithelial cells that line the airways of the respiratory system.
What is a flagellum?
A flagellum (plural = flagella) is an appendage larger than a cilium and specialized for cell locomotion.
What is a centriole?
A centriole can serve as the cellular origin point for microtubules extending outward as cilia or flagella or can assist with the separation of DNA during cell division.
What is the microfilament?
In contrast with microtubules, the microfilament is a thinner type of cytoskeletal filament
What is an intermediate filament?
As its name would suggest, an intermediate filament is a filament intermediate in thickness between the microtubules and microfilaments
All the following are functions of the smooth endoplasmic reticulum EXCEPT:
A) Lipid synthesis
B) Detoxification
C) Ca2+ storage
D) Protein synthesis
D) Protein synthesis
Protein synthesis occurs at ribosomes, which may be free or part of the rough ER.
The ________ is considered the “post office” of the cell because its job is to sort and package products from the Rough ER into vesicles and deliver the products to their correct location within the cell.
A) Ribosome
B) Golgi apparatus
C) Smooth ER
D) Mitochondria
B) Golgi apparatus
Which cell type is likely to contain the most mitochondria?
A) Red blood cell
B) Bone cell
C) Liver cell
D) Muscle cell
D) Muscle cell
The liver is primarily responsible for detoxifying the blood before it travels throughout the body. Therefore, you would expect liver cells to contain an exceptionally high number of:
A) Peroxisomes
B) Nucleoli
C) Ribosomes
D) Mitochondria
A) Peroxisomes
The cells lining the airways of the respiratory system secrete mucus to trap particles from incoming air, and also contain cellular extensions that beat rhythmically to push the mucus upwards towards the throat so that it can be coughed out. Which type of cellular extensions are described here?
A) Microfilaments
B) Cilia
C) Microvilli
D) Flagella
B) Cilia
The glycocalyces on a person’s cell membrane are _______.
A) Genetically unique
B) Found on the inside of the plasma membrane
C) Protein channels
D) Important to the hydrophobic head portions of the membrane
A) Genetically unique
They are a part of a person’s genetic make up.
A pentose sugar is a part of the monomer used to build which type of macromolecule?
A) Polysaccharides
B) Nucleic acids
C) Phosphorylated glucose
D) Glycogen
B) Nucleic acids
In DNA, nucleotide bonding forms a compound with a characteristic shape known as a(n) ________.
A) Beta chain
B) Pleated sheet
C) Alpha helix
D) Double helix
D) Double helix
The nucleus and mitochondria share which of the following features?
A) protein-lined membrane pores
B) a double cell membrane
C) the synthesis of ribosomes
D) the production of cellular energy
B) a double cell membrane
Phospholipids are considered ________ because they contain both a hydrophilic region and a hydrophobic region within the same molecule.
A) hydrophobic
B) hydrophilic
C) amphipathic
C) amphipathic
What is a nuclear envelope?
Like most other cellular organelles, the nucleus is surrounded by a membrane called the nuclear envelope. This membranous covering consists of two adjacent lipid bilayers with a thin fluid space in between them.
What is a nuclear pore?
A nuclear pore is a tiny passageway for the passage of proteins, RNA, and solutes between the nucleus and the cytoplasm.
What is a nucleolus?
There also can be a dark-staining mass often visible under a simple light microscope, called a nucleolus (plural = nucleoli).
What is a chromatin?
Within the nucleus are threads of chromatin composed of DNA and associated proteins
What is histone?
Along the chromatin threads, the DNA is wrapped around a set of histone proteins.