CHAPTER 2 THE CELL

Yes, membrane proteins can move within the lipid bilayer.

Ribosomes.

They change lipid composition in response to changing temperature.

The clarity of the image or the minimum distance of two distinguishable points.

Through bulk transport methods such as exocytosis or endocytosis.

A solution with the same solute concentration as that inside the cell.

It can strengthen bonds and foster goodwill.

A membrane-bound organelle found in plant or fungal cells.

It is a complex and dynamic player in the cell's compartmental organization.

A high proportion of unsaturated hydrocarbon tails.

Weak hydrophobic interactions.

Membranous sacs within chloroplasts.

They facilitate the movement of amoebas.

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To maintain the shape of the cell, including the nucleus.

Proteins that allow passage of hydrophilic substances across the membrane.

They cause the protrusion of pseudopodia in white blood cells (WBC).

Catalase.

To visualize cells that are too small to see with the naked eye.

The ability of a surrounding solution to cause a cell to gain or lose water.

A solution is hypotonic if the solute concentration is less than that inside the cell.

To maintain their crispness.

Net diffusion of water is from the surrounding solution to the inside of the cell.

They are more fluid.

By acting as receptors for signaling molecules.

Solute binding to receptors.

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One DNA molecule associated with proteins, called chromatin.

To acknowledge kindness or help received.

It varies in many species, such as having a high proportion of unsaturated hydrocarbon tails in fish that live in extreme cold.

A cell's ability to distinguish one type of neighboring cell from another.

Multifunctional theranostic applications of biocompatible green-synthesized colloidal nanoparticles.

They interact with the surface molecules of other cells, facilitating cell-cell recognition.

A solution is hypertonic if the solute concentration is greater than that inside the cell.

Tight junctions, desmosomes, and gap junctions.

Temperature.

Net diffusion of water is from inside the cell to the surrounding solution.

Visible differences in brightness between parts of the sample.

They assist in the movement of molecules across the cell membrane, either passively or actively.

When the solute concentration is equal on both sides.

Bound to the surface of the membrane.

A pair of centrioles.

They penetrate the hydrophobic core of the membrane.

A process where molecules are taken up when extracellular fluid is 'gulped' into tiny vesicles.

Cellulose.

The control of solute concentration and water balance.

One or several vacuoles.

Coated vesicles.

Proteins that penetrate the hydrophobic core of the lipid bilayer.

Organelles found only in plants and algae.

Cellulose.

Chitin.

Communication between brain cells.

Channels that perforate plant cell walls.

A bilayer with hydrophobic tails inside and hydrophilic heads exposed to water.

0.25 μm.

Proteins that are part of, or interact with, cell membranes.

Microscopes.

Plants use different but related steroid lipids.

Down the concentration gradient.

Water will tend to leave the cell.

It helps to keep the cells turgid by maintaining water pressure.

They will gain water, swell, and lyse (burst).

They provide mechanical strength by anchoring adjacent cells together.

To serve as the basic unit of life.

To allow communication and the passage of ions and small molecules between adjacent cells.

They become wilted and lose their crispness.

Photoautotroph, chemoautotroph, photoheterotroph, and chemoheterotroph.

The structure and function of isolated organelles.

They provide structural support and stability.

From preexisting cells.

They are involved in the invagination and evagination of the membrane.

Appendages loosely bound to the surface of the membrane.

Movement of small molecules that requires energy and a transport protein.

The fluid nature of the lipid bilayer permits movement.

At cool temperatures, cholesterol maintains fluidity by preventing tight packing.

Cylindrical structures that are part of the cytoskeleton in eukaryotic cells.

It consists of flattened membranous sacs called cisternae.

Temperature, oxygen concentration ([O2]), amount of mitochondria, surface area, and inhibitors.

Plants, prokaryotes, fungi, and some protists.

It allows for the movement of lipids and proteins within the membrane.

They are either continuous or connected via transfer by vesicles.

Concentration gradient.

Staining enhances contrast, but most procedures require that cells be fixed (preserved).

The concentration gradient.

There is no net movement of water into the cell.

Metabolic requirements.

Transmission electron microscope (TEM) and scanning electron microscope (SEM).

They have DNA in a nucleus that is bounded by a double membrane.

Turgid (very firm).

No, they have microtubule organizing centers that function similarly.

They help some specialized cells perform their functions, such as nail-producing cells forming nails.

Microscopes and the tools of biochemistry.

At warm temperatures (such as 37ºC), cholesterol restrains the movement of phospholipids.

They switch from a fluid state to a solid state.

0.25 μm.

It increases to prevent membrane solidification during winter.

Microvillus.

It protects them from rupturing due to excess water movement.

To visualize cells.

Unsaturated fatty acids increase membrane fluidity.

They will lose water, shrivel, and likely die.

Only in animal cells.

To work properly.

The proton pump.

The food vacuole fuses with the lysosome, and hydrolytic enzymes digest food particles.

Lenses refract (bend) the light to magnify the image.

It maintains the potential difference between the inside and outside of nerve cells.

It is a selective barrier that allows sufficient passage of oxygen, nutrients, and waste.

Active hydrolytic enzymes.

Membrane-bound organelles.

Approximately 1 μm.

Preservation of specimens at very low temperatures.

Transport of substances across a membrane against their concentration gradient.

They enable the formation of the cleavage furrow.

They distribute and support organelles in the cytoplasm.

Primary cell wall and secondary cell wall.

Cholesterol is a membrane component that affects membrane fluidity at different temperatures.

Movement of small molecules across the cell membrane without energy input, possibly requiring transport proteins.

Fluidity affects both permeability and movement of transport proteins.

The ratio of an object's image size to its real size.

It maintains the shape of plant cells.

They cannot support protein function.

Robert Hooke.

A transport protein that generates voltage across a membrane, storing energy for cellular work.

Biocompatible green-synthesized colloidal nanoparticles.

Bigger than microfilaments, smaller than microtubules.

From high to low concentration.

A harder and usually thicker layer of the cell wall.

The concentration of solutes in the solution that cannot cross the membrane, relative to that inside the cell.

ATP.

Alcohol.

The sodium-potassium pump.

A research method used to separate cellular components.

Between the plasma membrane and the primary cell wall.

No, it does not need ATP.

The process of taking cells apart and separating the major organelles from one another.

Through the uptake mechanisms in young epidermal cells of roots.

1 μm.

It takes up water and swells until turgor pressure is exerted.

Water diffuses across the membrane at the same rate in both directions, resulting in no net movement.

They help maintain membrane fluidity in cold environments.

It regulates protein traffic and performs metabolic functions.

The diffusion of free water across a selectively permeable membrane.

Molecules released from vesicles binding to them.

A process where macromolecules are taken into the cell in vesicles.

To organize spindle fibers.

They have differences in membrane lipid composition.

It forms a pocket that deepens and pinches off to form a vesicle.

To prevent the passage of materials between cells.

They facilitate various functions such as transport, signaling, and cell recognition.

A beam of electrons.

Regularly arranged in parallel rows, perpendicular to those in upper or lower layers.

They cannot tolerate excessive water loss or uptake.

H2O soluble molecules and molecules not soluble in lipids, such as ions, nucleic acids, amino acids, and glucose.

The pressure of the cell contents against the cell wall, which keeps the plant firm and crisp.

They provide structural support and help in cell adhesion and communication.

Prokaryotic and Eukaryotic cells.

Nonspecific; it takes in any and all solutes.

They help separate the chromosome copies in dividing cells.

Keratin filaments in hairs and nails.

It fuses with a lysosome to digest the particle.

Electrochemical gradient.

It serves as the main microtubule organizing center in cells.

Double membrane.

They can contract, causing movement.

It acts as a membrane factory for the cell.

They get energy from light and receive carbon by ingesting other organisms.

Yes, more substances can still be taken in.

Glucose.

Intermembrane space.

Molecules that bind to membrane proteins.

The tendency for molecules of any substance to spread out evenly into the available space.

The movement of large molecules like proteins and polysaccharides via vesicles.

It provides mechanical strength and support.

Plasma membranes and cell walls.

The types of lipids present in the membrane.

A membranous sac of hydrolytic enzymes that can digest all kinds of macromolecules.

Thin, thread-like structures that are also part of the cytoskeleton.

Chromosomes.

Actin filaments.

Phagocytosis.

It consists of thin layers found just outside of the plasma membrane.

The egestion or secretion of substances from the cell.

They serve as identification tags recognized by other cells.

4 long strands of α helix coiled fibrous proteins.

25 nm.

They contain both hydrophobic (water-fearing) and hydrophilic (water-loving) regions.

It enables scientists to determine the functions of organelles.

It focuses a beam of electrons through a specimen.

Negative.

Smaller molecules diffuse more easily and quickly.

Down the concentration gradient.

The movement of molecules from an area of higher concentration to an area of lower concentration.

It determines the 3D shape of the cells.

Non-polar molecules diffuse more easily than polar molecules.

They consist of 9 pairs of microtubules and 2 singlet microtubules.

It allows visualization of structures in their cellular environment without the need for preservatives.

Chloroplasts, Leucoplasts, and Chromoplasts.

Dynein arms.

Passive transport, active transport, and facilitated diffusion.

0.5 μm.

A type of active transport that moves sodium out of the cell and potassium into the cell.

0.5 μm to 1 μm.

The volume of the cell remains stable.

Approximately 0.5 μm.

Rarely.

Nuclear envelope, endoplasmic reticulum, Golgi apparatus, lysosomes, vacuoles, and plasma membrane.

It is crucial for various cellular functions, including signaling and transport.

Regulates exchanges with its environment and surrounding cells.

8 - 12 nm.

In young cells and cells that are not highly differentiated, such as meristem, parenchyma, and collenchyma.

The uptake of substances into the cell.

Identifying cell walls and naming them 'cells'.

They shape the cell by forming the cytoskeleton.

They fractionate cells into their component parts through differential centrifugation.

A process where a cell engulfs a particle by extending pseudopodia around it.

It is considered a microtubule-organizing center.

It likely refers to specific sections or chapters in a textbook or educational resource.

Integral proteins that span the membrane.

Cell size affects the efficiency of nutrient uptake and waste removal; smaller cells have a higher surface area-to-volume ratio, facilitating these processes.

It gives mechanical support to the cell.

They use a contractile vacuole to pump excess water out of the cell.

Coat proteins, forming coated vesicles.

Basal body.

They pump excess water out of protist cells.

The measurement of organisms and cells, often expressed in micrometers or nanometers.

Actin and myosin.

A network of membranes that includes the nuclear envelope, endoplasmic reticulum, Golgi apparatus, lysosomes, and vesicles.

7 nm.

The endoplasmic reticulum (ER).

Cytology, the study of cell structure.

By acting as receptors for signaling molecules.

It involves a membrane protein binding to a chemical messenger, causing a conformational change that relays the message inside the cell.

Outer doublets.

Yes, most lipids and some proteins can move sideways.

Converts hydrogen peroxide (H2O2) to water and oxygen (O2).

They are amphipathic.

Bound to the endoplasmic reticulum or free in the cytoplasm.

Transporting substances across the cell membrane.

Peripheral proteins and integral proteins.

Applied Microbiology and Biotechnology.

Lipids and proteins, with carbohydrates also being important.

Modifies products of the endoplasmic reticulum (ER).

Embedded in the bilayer.

Protein tubulin.

Water will tend to enter the cell.

A network of fibers and proteins outside of cells that provides structural and biochemical support.

Controls cellular activities.

Lignin, forming a hard and impervious layer.

Shorter fatty acid tails increase membrane fluidity.

It condenses to form discrete chromosomes.

It sorts and packages materials into transport vesicles.

5 nm.

Nonpolar amino acids, often coiled into α helices.

It affects the efficiency of nutrient and waste exchange.

Prokaryotic cells lack a nucleus and membrane-bound organelles.

They completely span the membrane.

They provide a hydrophilic channel for selective solute transport or shuttle substances by changing shape.

Attachment structures on the surface of some prokaryotes.

ATP and a carrier protein.

Sodium (Na) and Potassium (K) ions.

0.5 – 5 μm.

Facilitating the movement of substances across the cell membrane.

A specific receptor site.

The arrangement of microtubules within the centriole.

Uses lasers and special optics for 'optical sectioning' of fluorescently-stained specimens.

Unicellular, multicellular, or filamentous.

From lower solute concentration to higher solute concentration.

It passes light directly through the specimen, resulting in little contrast unless the cell is naturally pigmented or stained.

Toward the cytosol and extracellular fluid inside and outside the membrane.

In a small cylindrical shape, perpendicular to one another.

To prevent membrane solidification.

The proton pump, which actively transports hydrogen ions (H+) out of the cell.

A vesicle for transport.

The voltage across a membrane.

Higher temperatures increase the rate of diffusion.

In coated pits.

They become flaccid (limp) and the plant wilts.

Channel proteins and carrier proteins.

The membrane as a mosaic of protein molecules bobbing in a fluid bilayer of phospholipids.

The movement of substances down their concentration gradients across a membrane without energy expenditure by the cell.

No, they often form groups that carry out common functions.

A process where transport vesicles migrate to the membrane, fuse with it, and release their contents outside the cell.

They coordinate extracellular and intracellular changes.

They obtain energy chemically and carbon from fixing CO2.

Cross-linking proteins.

They hydrolyze ATP to actively pump substances across the membrane.

0.25 μm.

Site of photosynthesis.

They change their length very quickly depending on locations and functions.

Starch, found in roots.

About 100 μm.

They are dynamic.

Its surface is studded with ribosomes.

They can appear blurry, especially in relatively thick tissue.

Complex, with a '9+2' pattern of triplet microtubules.

No spindle during cell division.

To isolate and study different organelles within a cell.

Cholesterol helps to stabilize membrane fluidity across temperature changes.

A type of cytoskeletal filament.

The pressure exerted by the inelastic cell wall on a swollen plant cell.

It enhances contrast in unstained cells by amplifying variations in density, making it useful for examining living, unpigmented cells.

The net movement of solute stops.

Gap junctions and tight junctions.

Only secondary coiled structure.

Movement of substances across the plasma membrane without the use of energy.

As fluid mosaics of lipids and proteins.

Phagocytosis.

They get energy from light and carbon from fixing CO2.

It is specific.

A smooth outer membrane and an inner membrane folded into cristae.

Secretory proteins surrounded by membranes.

The diffusion of water across a selectively permeable membrane.

Microtubules, microfilaments, and intermediate filaments.

Larger cells may have lower metabolic rates per unit volume, while smaller cells can maintain higher metabolic activity due to better nutrient exchange.

Hydrophobic molecules and very small uncharged polar molecules.

The movement of substances against their concentration gradient, requiring energy.

The process where many hydrophilic substances diffuse through membranes with the assistance of transport proteins.

It encloses the cytoplasm.

Calcium ions.

ATP.

Intermediate filaments made of sturdy keratin proteins.

A typical rod-shaped bacterium, 0.5 μm.

May be present and made of glycoprotein.

Chloroplasts.

Visible light is passed through a specimen and then through glass lenses.

Phospholipids.

They can function as enzymes to catalyze reactions.

Centrifugation.

They guide the movement of organelles.

A larger surface area increases the rate of diffusion.

The inflow and outflow of material to and from the nucleus.

They are randomly arranged.

They lose water, causing the cell to shrivel and the membrane to pull away from the cell wall.

A structure located within the nucleus that is the site of ribosomal RNA (rRNA) synthesis.

Acts as the site of ribosome construction.

Plasmodesmata.

Elongated shapes can enhance the cell's ability to cover more area for absorption or to facilitate movement.

Secretory cells.

To increase the surface area for biochemical reactions.

The variety of different cell types and their functions within an organism.

Free ribosomes and mitochondrial DNA.

Prokaryotic and Eukaryotic cells.

They can be organized as a team to carry out sequential steps of a metabolic pathway.

Chlorophyll.

Carotenoid pigments (red, orange, and yellow in color).

They transport materials between different organelles.

They help cells stick to each other and to the extracellular matrix.

Ions, sugars, amino acids, and other small molecules.

Receptor-mediated endocytosis.

Absent.

Plasma membrane.

Certain macromolecules.

A network of fibers that organizes structures and activities in the cell.

Differences in the distribution of positive and negative ions.

By serving as markers for cell identification.

A membranous sac called a food vacuole.

The chemical force (ion's concentration gradient) and the electrical force (membrane potential effect).

It has bound ribosomes that secrete glycoproteins.

They divide the cytoplasm into compartments, allowing specialized enzymes to function better.

Plasmolysis.

They have a nucleus and membrane-bound organelles.

Eukaryotic cells are generally much larger than prokaryotic cells.

In plant cells.

In the nucleoid region, which is not enclosed by a membrane.

Reserves of important organic compounds and water.

The ER membrane is continuous with the nuclear envelope.

It detoxifies drugs and poisons.

0.1 μm.

They have a nucleus and membrane-bound organelles.

By acting as enzymes that catalyze biochemical reactions.

A stack of thylakoids.

40 to 60 grana.

Fine, simple & only consists of one microtubule.

It may or may not need a transport protein.

They bond to membrane proteins, helping maintain cell shape and stabilize protein location.

Biochemistry and cytology.

It focuses a beam of electrons onto the surface of a specimen.

In the region between the plasma membrane and the nucleus.

By transport proteins in the membrane.

Equilibrium.

Cylindrical structures found in the centrosome, involved in cell division.

To exaggerate differences in density, making the image appear almost 3D.

More than half.

It may have its active site exposed to substances in the adjacent solution, facilitating enzymatic activity.

Capture of light energy.

It modifies, sorts, and packages proteins and lipids for secretion or delivery to other organelles.

Channel proteins and carrier proteins.

It is a rigid structure outside the plasma membrane.

It allows for specialization and adaptation to different functions and environments.

Triplet arrangement.

Cellular drinking.

DNA is circular, lies free in the cytoplasm, and is naked.

Smaller types, 70 S (18 nm).

Cell shape can determine the cell's ability to perform specific functions, such as movement, communication, and interaction with other cells.

Cilia, flagella, and spindle fibers.

A hypotonic environment.

Volume grows proportionately more than surface area.

With the extracellular side of the membrane.

Longer distances decrease the rate of diffusion.

The process of transporting substances across a membrane with the help of carrier proteins.

It synthesizes lipids.

They synthesize proteins.

10 – 100 μm.

Subunits of proteins that can slide over one another.

They serve as markers for cell identification.

A sharp image due to the subtraction of out-of-focus fluorescence.

They are locomotion organelles.

Few organelles, none are membrane-bound.

Heart muscle and animal embryos.

Absent.

None.

All living things are composed of cells.

They are recycled to the plasma membrane by the same vesicle.

Passive transport of cations into and anions out of the cell.

Hereditary information.

The plant will wilt and may die.

It regulates the movement of substances in and out of the cell.

Insulin, secreted by cells in the pancreas.

By tagging the molecules with fluorescent dyes or antibodies.

Longitudinal section.

Ultraviolet radiation.

By providing insight into the spike-protein structure.

It lacks ribosomes.

A jelly-like outer coating of many prokaryotes.

Cytoplasmic channels from one cell to an adjacent cell.

They are necessary for communication between cells in many types of tissues.

Three types.

Bigger types, 80 S (22 nm).

It moves from an area of higher concentration to an area of lower concentration, influenced by electrical forces.

The movement of substances across a membrane against their concentration gradients using energy, usually supplied by ATP.

They consist of 9 triplets of microtubules.

It reveals protein complexes and subcellular structures.

They obtain both energy and carbon from organic compounds by ingesting organisms or materials with carbon.

Fluid from moving across a layer of cells.

They lack a nucleus and membrane-bound organelles.

Unicellular or filamentous.

To fasten cells together into strong sheets.

Peptidoglycan.

10 to 100 thylakoids.

Many organelles, some are membrane-bound.

Plasma membrane.

Smooth ER and Rough ER.

They contain enzymes that break down waste materials and cellular debris.

It has a binding site that fits the shape of a specific chemical messenger, such as a hormone.

Nerve cells are green, support cells are red, and regions of overlap are yellow.

Mitochondria.

Cells.

A cell without a true nucleus or other internal membranes.

Plasma membrane.

Cellulose and chitin.

DNA is linear and contained in the nucleus.

Spindle present during cell division.

The internal fluid of the chloroplast.

By providing a framework that supports the cell's shape.

May be present for attachment.

Folding of plasma membrane.

A cell with a true nucleus and organelles surrounded by a membrane.

Prokaryotic cells lack a true nucleus and membrane-bound organelles, while eukaryotic cells have both.

The outer membrane of the nuclear envelope is continuous with the endoplasmic reticulum.

Cellular eating.

Channels that connect granum.