A tour of the cell & The working cell Q&A Flashcards
What is the definition of Endoplasmic reticulum?
A network of membranes involved in protein synthesis and lipid metabolism
True or False?
Are Ribosome responsible for lipid synthesis?
False
Ribosomes are not responsible for lipid synthesis. Ribosomes are cellular organelles that are responsible for protein synthesis. Lipid synthesis occurs in the endoplasmic reticulum and other organelles such as the smooth endoplasmic reticulum and the Golgi apparatus. Lipids are essential components of cell membranes and serve as energy storage molecules.
What is the primary role of lysosomes in the recycling process within a cell?
Breaking down waste materials
Lysosomes
- Lysosomes are membrane-bound organelles containing enzymes that break down cellular waste and old organelles for recycling purposes.
- The primary role of lysosomes in the recycling process within a cell is to degrade unnecessary materials into simpler components.
- By breaking down waste materials, lysosomes help maintain cellular homeostasis and provide essential building blocks for new cellular processes.
What is the role of mitochondria in cellular respiration and energy production?
Mitochondria are essential for cellular respiration and energy production. They convert glucose and oxygen into ATP, the primary energy source for cells. Along with generating ATP, mitochondria also contribute to cell death regulation and calcium signaling.
True or false?
The cytoskeleton is a singular, rigid structure that gives shape to the cell.
False;
The statement is false because the cytoskeleton is not a singular, rigid structure.
Cytoskeleton is
it is a dynamic network of protein filaments that provide structural support to the cell and help maintain its shape.
Cytoskeleton is made up of
three main types of filaments: microtubules, actin filaments, and intermediate filaments, each with different functions and properties. These filaments are constantly being assembled and disassembled, allowing the cell to change shape, move, and carry out various cellular processes.
Plasma membrane fluidity
The fluidity of the plasma membrane allows for cell movement and growth
Temperature can affect the fluidity of the plasma membrane
What is the role of cytoplasm ion supporting cellular functions and organelles?
The cytoplasm is vital for supporting cellular functions and organelles. It serves as a medium for metabolic reactions, provides structural support, houses organelles, facilitates molecule transport, and maintains cell shape and integrity.
Which scientific principle states that all organisms consist of cells?
Cell theory
Fill in the blank:
The ________ provides structural support and protection to the cell membrane.
Cell wall
* The cell wall is a rigid layer found outside the cell membrane in plant cells, fungi, and some prokaryotes. * It provides structural support and protection to the cell membrane by maintaining the cell's shape and protecting it from external factors.
True or False?
Are Chloroplasts the same as Mitochondria in plant cells
False
Chloroplasts are responsible for photosynthesis, the process by which plants convert light energy into chemical energy to produce glucose.
On the other hand, mitochondria are the powerhouses of the cell, where cellular respiration takes place to generate ATP, the energy currency of the cell.
How do be bacterial flagella generate movement?
By rotating like a propeller
True or False?
Ribosomes are always found attached to the cell membrane?
False; ribosomes are found in two locations within a cell: free floating in cytoplasm and attached to the endoplasmic reticulum (ER)
What is the primary function the cytoskeleton in cells?
Providing structural support
Cholesterol is a
component of the plasma membrane
Tru or False?
Cytoplasm is composed entirely of enzymes, with no presence of water, salts, organelles?
False;
Cytoplasm is a gel-like substance that fills the cell and surrounds the organelles. It is composed of water, salts, and various organic molecules, including enzymes. Cytoplasm provides a medium for many cellular processes to occur, such as metabolic reactions, protein synthesis, and transportation of molecules. Additionally, cytoplasm contains various organelles, such as ribosomes, mitochondria, and the endoplasmic reticulum, which perform specific functions within the cell.
What role does the plasm membrane play in maintaining cell structure and function?
The plasma membrane is essential for cell structure and function as it acts as a selective barrier, regulates substance movement, enables cell communication, provides structural support, and houses important proteins and receptors for signaling and recognition.
Thylakoid membranes are
interconnected to form stacks called grana
True or False?
Cytoplasm is a jelly-like substance that fills the cell and surrounds the organelles?
True;
Cytoplasm is a jelly-like substance that fills the interior of the cell and surrounds the organelles. It is a semi-fluid matrix composed of water, salts, and organic molecules where many cellular activities take place. Cytoplasm provides support to the organelles and helps in the movement of materials within the cell.
What is the definition of Cell theory?
The scientific principle that states all living organisms are composed of cells.
What are small cellular structures responsible for protein synthesis in living organisms?
Ribosomes
What is the definition of Cytoskeleton?
A network of protein filaments that provides structural support to cells
True or False?
Are Chloroplasts found in animals cells?
False;
Chloroplasts are organelles found in plant cells and protists.
Chloroplasts are responsible for photosynthesis, the process by which plants convert sunlight into energy.
ANIMAL Cell do not have chloroplasts because they do not perform photosynthesis.
What is the function of flagella in single-celled organisms such as bacteria?
Flagella in single-celled organisms, such as bacteria, facilitate movement by rotating and propelling the cell through liquid environments.
What unique feature do mitochondria possess that distinguishes them from other organelles?
They contain their own DNA (mtDNA)
During which phase of the cell cycle does the nucleus divide, ensuring that each daughter cell receives a complete set of chromosomes?
Mitosis
How do the cell walls of fungi and plants differ?
Fungi cell walls are made of chitin, while plant cell walls are made of cellulose
True or False?
The plasma membrane is made up entirely of phospholipids and does not contain any proteins?
False;
Plasma membrane is composed of a phospholipid bilayer with embedded proteins
Which type of endoplasmic reticulum (ER) is responsible for detoxification and lipid metabolism within cell?
Smooth endoplasmic reticulum (SER)
Compare and contrast the functions of lysosomes and vacuoles
Lysosomes function in cellular waste disposal
Vacuoles store water, nutrients, and waste materials
True or False?
According to Cell theory, the basic unit of structure and organization in organisms is the nucleus
False
True bout the role of the cytoskeleton in cell movement?
The cytoskeleton is involved in cell crawling and migration
The cytoskeleton plays a role in the movement of cilia and flagella
What is the structural arrangement of microtubules in flagella and cilia known as?
9 + 2 array
True about chloroplasts
chloroplasts are double-membrane organelles found in plant cells.
chloroplasts contain their own DNA and ribosomes
chloroplasts are responsible for photosynthesis, converting light energy into chemical energy
What are the two membrane of the mitochondria called?
outer and inner membrane
what is the primary component of the cell wall in Gram_positive bacteria?
Peptidoglycan
The catalytic cycle of Enzyme
- Substrate enters the active site
- Substrate and enzyme change shape
- Product is expelled
- Enzyme reverts to original configuration
What is a key feature of the cytoplasm?
it has a semi-solid consistency
How do flagella differ from cilia in term of their structure?
flagella are longer and fewer in number
Compare and contrast the structure of lysosomes and peroxisomes?
both lysosomes and peroxisomes are membrane-bound organelles involved in cellular waste disposal
Compare the structural characteristics of microfilaments and intermediate filaments in the cytoskeleton.
Microfilaments are thin, composed of actin monomers, and involved in cell movement, while intermediate filaments are thicker, made of various proteins, and provide mechanical support.
True or False?
Chloroplasts contain chlorophyll, a pigment that absorb light energy for photosynthesis
True
Chloroplasts are organelles found in plant cells that contain chlorophyll, a green pigment. Chlorophyll is responsible for capturing light energy from the sun, which is then used in the process of photosynthesis to convert carbon dioxide and water into glucose and oxygen. This absorption of light energy by chlorophyll is essential for plants to produce their own food and is a key step in the photosynthetic process.
What enables chloroplasts to synthesize some proteins independently of the cell’s nucleus?
They have their own DNA and ribosomes.
What is the chief component of prokaryotic cell walls?
Peptidoglycan
- Prokaryotic cell walls provide structural support and act as a barrier against environmental stresses.
- Peptidoglycan is a polymer made of sugar and amino acids found in bacteria, defining their cell wall composition.
- Understanding peptidoglycan structure helps in developing antibiotics targeting bacterial cell walls to combat infections.
Compare and contrast the composition of cytoplasm and cytosol
Cytoplasm includes cytosol along with organelles, while cytosol refers to the liquid portion of the cytoplasm
Compare and contrast the function of bacterial flagella and pili
Bacterial flagella are used for locomotion, while pili are used for attachment
True or False?
Mitochondria have their own genetic material separate from the nucleus of the cell
True
Statements true about Lysosomal Storage disease
Lysosomal storage disorders result from deficiencies in lysosomal enzymes.
Lysosomal storage disorders can lead to the accumulation of undigested substances within cells
Where do ribosomes get the instructions to synthesize protein
From messenger RNA (mRNA)
_____________ is a major component of plant cell walls
Cellulose
What is the primary structure of the plasma membrane according to fluid mosaic model?
A bilayer of phospholipids with embedded proteins
Compare and contrast the location of mitochondria and peroxisomes within a cell.
Mitochondria and peroxisomes are both present in the cytoplasm of a cell, but mitochondria are more abundant.
Lysosomes
- Lysosomes are membrane-bound organelles found in eukaryotic cells because they are surrounded by a lipid bilayer membrane, which separates their contents from the cytoplasm.
- Lysosomes are not involved in protein synthesis. Instead, they are responsible for the degradation and recycling of cellular waste materials, such as damaged organelles or foreign substances.
- Lysosomes contain hydrolytic enzymes that break down macromolecules, such as proteins, nucleic acids, carbohydrates, and lipids. These enzymes function optimally at an acidic pH, allowing lysosomes to efficiently break down and recycle cellular components.
What are the primary components of a ribosome?
rRNA and polypeptides
What is the primary function of flagella in cells?
To move the entire cell
Compare and contrast microtubules and microfilaments in the cytoskeleton
Microtubules are larger in diameter and are involved in cell shape and cell division, while microfilaments are thinner and play a role in cell movement and support
True or False?
Are Chloroplasts responsible for cellular respiration in cells?
False;
This statement is false because chloroplasts are actually responsible for photosynthesis, not cellular respiration. Photosynthesis is the process by which plants, algae, and some bacteria convert light energy into chemical energy stored in glucose, while cellular respiration is the process by which cells break down glucose to release energy. Cellular respiration takes place in the mitochondria of cells, not in the chloroplasts.
True about the function of the function of the nucleus?
The nucleus controls the activities of the cell.
The nucleus contains the genetic information of the cell
The nucleus regulates gene expression
Compare and contrast isotonic and hypertonic solutions
In an isotonic solution, the solute concentration is the same inside and outside the cell, resulting in no net movement of water. In a hypertonic solution, the solute concentration is higher outside the cell than inside, causing water to move out of the cell.
Compare and contrast competitive and noncompetitive enzyme inhibition in terms of their effect on enzyme kinetics
Competitive inhibition increase the apparent Km of the enzyme, while noncompetitive inhibition decreases the Vmax of the enzyme.
True or False?
Diffusion occurs when particles move from an area of low concentration to an area of high concentration
False;
Diffusion actually occurs when particles move from an area of high concentration to an area of low concentration
True or False?
Feedback inhibition is a way of regulating enzyme activity in a cell, where the product of a metabolic pathway inhibits an enzyme involved early in the pathway
True;
Feedback inhibition is a way of regulating enzyme activity in a cell, where the product of a metabolic pathway inhibits an enzyme involved early in the pathway. This is true because feedback inhibition helps maintain homeostasis by preventing the overproduction of certain molecules. When the product of a metabolic pathway accumulates to a certain level, it binds to and inhibits the activity of an enzyme early in the pathway. This inhibition slows down the overall rate of the pathway, preventing excessive production of the product. Once the product concentration decreases, the inhibition is relieved, and the pathway can resume its activity. This mechanism ensures that the cell produces only the necessary amount of a particular molecule, avoiding wasteful energy expenditure and maintaining a balanced metabolic state.
In a hypotonic environment, water moves into the cell, which can cause it to burst or lyse
True;
In a hypotonic environment, the concentration of solutes outside the cell is lower than inside the cell. This creates a concentration gradient that drives water into the cell through osmosis. As water moves into the cell, it can cause the cell to swell and potentially burst or lyse due to the increase pressure inside the cell
Which term is used to describe a solution that causes a cell to swell due to osmosis?
Hypotonic;
Hypotonic - A solution with lower solute concentration than another solution.
* Hypotonic solutions cause cells to swell or burst due to an influx of water. * In biological systems, hypotonic environments can disrupt cell function and lead to cellular damage. * Osmosis occurs when water moves from a hypotonic solution to a hypertonic solution.
Feedback inhibition refers to a process where the product of a metabolic pathway enhances the activity of an enzymes involved early in the pathway
False;
Feedback inhibition actually refers to a process where the end product of a metabolic pathway inhibits the activity of an enzyme involved early in the pathway. This mechanism helps regulate the rate of the pathway by preventing the overproduction of end products.
A hypertonic solution has a lower concentration of solutes than another solution
False;
A hypertonic solution actually has a higher concentration of solutes compared to another solution. In a hypertonic solution, there are more solute particles outside the cell than inside, causing water to move out of the cell through osmosis, potentially causing the cell to shrink or shrivel.
Compare and contrast the role of ATP in anabolism versus catabolism
ATP provides energy for anabolism, which builds complex molecules, and is released in catabolism, which breaks down complex molecules.
In a hypotonic environment, water moves out of the cell, causing it to shrink or shrivel
False;
In a hypotonic environment, the concentration of solutes outside the cell is lower than inside the cell. As a result, water moves into the cell through osmosis, causing it to swell or even burst, not shrink or shrivel.
What does it mean for a solution to be isotonic?
The solute concentration is equal on both sides of the membrane
What happens to the diffusion rate when the distance that particles must travel increases?
The diffusion rate decreases because it take longer for particles to move.
Compare and contrast osmosis and diffusion
Osmosis is the movement of water molecules across a selectively permeable membrane, while diffusion is the movement of particles from an area of high concentration to an area of low concentration.
True about concentration gradient
- Diffusion occurs from an area of high concentration to an area of low concentration
- Concentration gradient is the difference in concentration between two areas
- Concentration gradient is the primary factor determining the direction of diffusion
True about Osmosis
Aims to equalize the concentration of solute on both sides of the membrane
Can lead to the swelling or shrinking of cells
In what way do the efficiency and spontaneity of coupled reactions compare to those of independent reactions?
Coupled reactions are generally more efficient and can drive non-spontaneous reactions by harnessing the energy from spontaneous ones, while independent reactions must be spontaneous to proceed without external energy input.
In what way do free ribosomes and bound ribosomes contribute differently to cellular processes?
Free ribosomes are involved int eh synthesis of cytoplasmic and organelles proteins, while bound ribosomes are involved in membrane protein synthesis
Compare and contrast the roles of DNA and RNA in protein synthesis, highlighting their structural differences and functions
DNA serves as the genetic blueprint and remains in the nucleus, while RNA carries out protein synthesis in the cytoplasm. DNA is double-stranded, while RNA is single-stranded.
what is the procedure called when an objects size is increased for detailed examination?
Magnification
the process of making an object appear larger in size.
in microscopy, what is the term used to describe the difference in light intensity between an object and its background?
contrast
difference in light between an object and its background in a microscope
___________ is the ability to distinguish two separate points in an image
resolution
the ability to distinguish two separate points in an image
Which function of enzymes allows them to accelerate chemical reactions in biological systems?
Lowering activation energy
In non-competitive inhibitor, where does the inhibitor binging to the enzyme?
Allosteric site
- Non-competitive inhibition involves the inhibitor binding to a site on the enzyme other than the active site.
- The binding of the inhibitor at the allosteric site causes a conformational change in the enzyme, reducing its activity.
- This type of inhibition does not compete with the substrate for the active site, making it distinct from competitive inhibition.
What characteristic distinguishes enzymes from reactants in a catalyzed reaction?
They are not consumed
How can the effect of competitive inhibition be counteracted in an enzymatic reaction?
increasing the substrate concentration
True or False?
Competitive Inhibition occurs when the inhibitor binds to the active site of the enzyme, preventing the substrate from binding?
False;
FALSE because competitive inhibition occurs when the inhibitor binds to a site on the enzyme other than the active site. This binding causes a conformational change in the enzyme that makes it less effective at binding to the substrate. As a result, the inhibitor competes with the substrate for binding to the enzyme, hence the name “competitive inhibition.
True about the Second Law of Thermodynamics?
Energy spontaneously tends to disperse
The total entropy of an isolated system can never decrease
true about contrast in genetics?
contrast in genetics refers to the differences in genetics traits among individuals
high genetic contrast between individuals indicates greater genetic diversity
True about magnification?
magnification affects the resolution of an image
magnification can be achieved using lenses or mirrors
