Biology HW 3 Connect

Which of the following are functions of lysosomes?

-Breaking down macromolecules in the cell -Digestion of substances taken in by endocytosis -Recycling of building blocks to make new molecules

Identify the four main components of all eukaryotic membranes.

-Cell surface markers -Interior protein network -Transmembrane proteins -Lipid bilayer

Choose all functions typically carried out by membrane proteins.

-Connect adjacent cells and hold them together -Attach the membrane to the cytoskeleton -Receive external chemical messages

The functions of the rough endoplasmic reticulum include which of the following?

-Glycoprotein synthesis -Protein sorting -Protein synthesis

Which of the following describes the sodium-potassium pump?

-It is an active transport mechanism. -It moves sodium ions and potassium ions across the membrane in opposite directions.

Which of the following is one of the four main components of all plasma membranes?

-Lipid bilayer -Transmembrane proteins -Interior protein network -Cell surface markers

Identify the fibers which are used in the cell division of animal cells.

-Microtubules -Actin

Which of the following are the main types of cytoskeletal fibers?

-Microtubules -Intermediate filaments -Actin filaments

What happens in a peroxisome?

-O2 is used to help break down lipids. -Highly reactive molecules such as hydrogen peroxide are generated.

Select the accurate statements concerning membrane fluidity.

-Phospholipids are relatively free to move laterally within the membrane. -Unanchored proteins are relatively free to move laterally within the membrane.

Which of the following are the three main types of endocytosis?

-Pinocytosis -Receptor-mediated endocytosis -Phagocytosis

Water is attracted to which kinds of solutes, forming hydration shells around them?

-Polar -Charged

Which of the following are similarities between mitochondria and chloroplasts?

-Presence of DNA -Presence of protein synthesizing ribosomes.

Which of the following are similarities between mitochondria and chloroplasts?

-Presence of protein synthesizing ribosomes -Presence of DNA

Which of the following are typical components of biological membranes?

-Proteins -Lipids

How does lipid composition affect membrane fluidity?

-Sphingolipids tend to make the membrane less fluid. -Saturated fatty acids tend to make the membrane less fluid because they pack together well.

Choose the three groups of lipids found in eukaryotic cells.

-Sterols -Sphingolipids -Glycerol phospholipids

Functions of the smooth endoplasmic reticulum include which of the following?

-Storage of calcium -Assembly of membrane lipids -Steroid synthesis

The two solutions shown in this diagram are separated by a selectively permeable membrane that allows water to pass through freely but prevents the passage of urea. Before equilibrium is reached, which of the following statements are true?

-The solution on the left is hypertonic. -The water level will rise on the left side of the U-tube -Net movement of water across the membrane is toward the left.

Select all true statements about cadherins.

-They are divided into two types: I and II. -They are Ca2+-dependent proteins. -They have an extracellular domain that can interact with other cadherins.

Select the statements that are true about ions and how they interact with membranes and their components.

-They are repelled by the hydrophobic interior of the lipid bilayer. -They interact well with polar molecules.

Which of the following statements about ion channels are true?

-They are used to transport ions across the membrane. -Some can be opened or closed in response to a specific stimulus.

When phospholipids are placed in water, they spontaneously form which of the following?

A bilayer

Which of the following is found in eukaryotic cells, but not in prokaryotic cells?

A nucleus

endocytosis

A process in which a cell engulfs extracellular material through an inward folding of its plasma membrane.

Identify the two main domains that contain prokaryotes?

Bacteria and Archaea

Which method of microscopy, commonly used to study lipid bilayers, was used to produce this image?

Freeze-fracture microscopy

The cell wall of which type of cell is composed of chitin?

Fungal

Bulk Transport: Exocytosis

Moves materials out of the cell in membranous vesicle, which migrates to and combines with plasma membrane, then emptied to outside

How do carrier proteins differ from channel proteins?

Only carrier proteins actually bind to the substance being transported.

In a parasitic relationship, one organism benefits but harms the second organism.

Parasites do not always live inside the other species.

Which of the following is a eukaryotic organelle in which O2 is used to help break down lipids?

Peroxisome

Some cells contain a nucleoid but not a

nucleus

Hydrophobic lipids are made soluble in the cytoplasm by being coated with ___________. The result is a lipid droplet.

phospholipids

The lipid bilayer that forms the core of all cell membranes is composed primarily of

phospholipids

The largest vacuoles, which can occupy most of the cell volume, are found in which type of cell?

plant

pinocytosis

process by which a cell takes in liquid from the surrounding environment

What are the two types of life forms?

prokaryotes and eukaryotes

Not all cells require a nucleus, for example, consider

prokaryotic cells, such as bacteria and archaea.

Ribosomes are responsible for ___________ synthesis in the cell.

protein / polypeptide

Which of the following are key functions carried out by membrane proteins?

-Transport specific ions and molecules across the membrane -Catalyze specific chemical reactions on the surface of the membrane -Receive external chemical messages -Function as cell-surface identity markers

The core of lipid droplets could contain which of the following lipids?

-Triglycerides -Sterols

Compared to the ER membrane, the plasma membrane contains more

-phosphatidylcholine -cholesterol -sphingomyelin

Transport that requires a cell to expend some of its own energy, typically from ___________, is called _______________ transport.

ATP ; Active

The digestive enzymes in the lysosomes are optimally active at which of the following pH ranges?

Acidic

During the contraction of muscle cells, which fiber is used?

Actin

Which of the following organisms would be able to manufacture its own food?

Any organism that has chloroplasts

Which of the following might explain (at least to some extent) the greater thermal stability of archaeal membranes?

Archaeal membranes contain saturated hydrocarbons in a monolayer.

Which of the following best describes the relationship between solute concentration and rate of diffusion during facilitated diffusion by carrier proteins?

As solute concentration increases, the rate of diffusion increases but eventually it remains constant once it reaches a maximum rate.

Why do ions need membrane transport proteins to help them cross the plasma membrane?

Because they are charged

Which type of transport proteins use energy from ATP indirectly?

Coupled transport proteins

Desmosomes

Cadherins bind to intermediate filaments

adherens junctions

Cadherins bind to microfilaments

Which type of movement is made possible by the arrangement of actin fibers?

Cellular crawling

Which structure is involved in eukaryotic cell division?

Centrosome

The flattened stacks of membrane typical of the Golgi apparatus are called which of the following?

Cisternae

Plasmodesmata

Cytoplasmic connections between the cell walls of plants

The eukaryotic cell structure involved in supporting the shape of the cell and anchoring organelles to fixed locations is the

Cytoskeleton

Which part of the cell's primary function is to support cell shape and anchor organelles to fixed locations?

Cytoskeleton

Net movement of a substance from a region where it has a higher concentration to a region where it has a lower concentration is called which of the following?

Diffusion

What type of microscope can be used to see the two phospholipid layers in a plasma membrane, as in this image?

Electron

What term describes a relationship, in which a smaller cell lives inside a larger cell?

Endosymbiosis

Which of the following is NOT one of the four main components of all plasma membranes?

Extracellular matrix

Which structure forms a protective layer rich in glycoproteins on the surface of animal cells?

Extracellular matrix

Diffusion that is assisted by a channel protein or a carrier protein is called ____________ diffusion.

Facilitated

When a channel protein or carrier protein assists in diffusion, which of the following is observed?

Facilitated diffusion

Gap junctions

Involves connexon proteins that create a pore to connect cells

Which of the following describes passive transport?

It does not require an expenditure of energy by the cell itself.

Tight junctions

Leak-proof seal that surrounds the cell

Which of the following are distinctly different in archaeal cells as compared to bacterial cells?

Lipids

Which of the following is the largest organelle present in eukaryotic cells?

Nucleus

Which of the following makes up the bilayer of every cell membrane?

Phospholipids

Which of the following can relatively easily move laterally within the plasma membrane?

Phospholipids and unanchored proteins

Which of the following junction types is only found in plants?

Plasmodesmata

Which of the following transport proteins use energy from ATP directly?

Protein pumps

The production of proteins is achieved by which of the following structures?

Ribosomes

Substances that cannot easily cross the lipid bilayer can still diffuse across the plasma membrane with the help of which of the following?

Specific channel proteins or carrier proteins

The ER membrane is typically thinner and more fluid than the plasma membrane and it contains more curvature. Why?

The ER membrane contains mainly unsaturated phospholipids.

Which is the largest of the internal membranes in a typical eukaryotic cell?

The endoplasmic reticulum

When phospholipids are placed in water, they spontaneously form a bilayer. Why?

The polar heads on the surface of the bilayer interact with water, while the nonpolar tails in the interior of the bilayer do not come into contact with water.

Which of the following is a defining feature of biological membranes?

The presence of two phospholipid sheets

This diagram shows two solutions separated by a membrane that allows water to pass through freely but prevents the passage of urea. Before equilibrium is reached, which statement is true?

The solution on the right has a higher concentration of free water molecules.

If two solutions have unequal concentrations of solutes, which one will be considered hypertonic?

The solution with the higher solute concentration

Coupled transport proteins (CTP) use a gradient that is generated by another protein. The gradient generating protein is using ATP.

Therefore the CTP is using the energy from ATP indirectly.

Which statement accurately describes bacterial flagella?

They consist of protein rings embedded in the plasma membrane and the cell wall with long fibers extending from them.

Select the statement that is true of transmembrane domains.

Transmembrane domains are composed of hydrophobic amino acids.

What is the name of carrier proteins that transport a single type of molecule or ion?

Uniporters

Eukaryotic flagella are actually outward projections of the cell's interior. The microtubules in the flagella originate from

a basal body

If you compare two aqueous solutions which differ in the amount of solutes dissolved, the aqueous solution with a higher concentration of solutes will have

a lower concentration of free water molecules

exocytosis

a process by which the contents of a cell vacuole are released to the exterior through fusion of the vacuole membrane with the cell membrane.

Which fiber is involved in cellular crawling?

actin

The main types of cytoskeletal fibers are ___________ filaments (also known as microfilaments), intermediate filaments and ______________

actin ; microtubules

The main types of cytoskeletal fibers are _____________ filaments (also known as microfilaments), intermediate filaments and _________________.

actin ; microtubules

While ___________transport requires the cell to expend some of its own energy, ____________transport does not.

active ; passive

A solution where water is the solvent is called a(n) ___________ solution.

aqueous

Prokaryotes are found in two domains:

bacteria and archaea

The microtubules in a eukaryotic flagellum are derived from a(n)

basal body

The two main categories of __________ __________are endocytosis and exocytosis.

bulk transport

Adherens junctions can be found in the cells of vertebrates and invertebrates and are based on the protein

cadherin

Of the 2 types of transport proteins that mediate facilitated diffusion, ___________ proteins actually bind with the substance being transported, while ______________ proteins simply provide a hydrophilic space for the substance to move through.

carrier ; channel

Of the 2 types of transport proteins that mediate facilitated diffusion, _____________ proteins actually bind with the substance being transported, while _______________ proteins simply provide a hydrophilic space for the substance to move through.

carrier ; channel

Antiporters

carry two substances across the membrane in opposite directions

Symporters

carry two substances across the membrane in the same direction

Cells that are part of the same tissue type recognize each other based on

cell-surface markers

The cell walls of plants and protists are made of the polysaccharide ___________ while the cell wall of fungal cells are made of the polysaccharide _______________

cellulose ; chitin

The cell walls of plants and protists are made of the polysaccharide _____________ while the cell wall of fungal cells are made of the polysaccharide _________________.

cellulose ; chitin

Many substances that are repelled by the hydrophobic interior of the lipid bilayer can readily diffuse across the plasma membrane with the help of specific ___________ proteins or ____________ proteins. These transporter proteins are typically transmembrane proteins.

channel ; carrier

Ion ____________ have a hydrated interior that spans the membrane and allows ions to diffuse through.

channels

In plants, photosynthesis occurs in semiautonomous organelles called

chloroplasts

The of the Golgi apparatus are flattened, stacked membrane folds.

cisternae

The internal portion of the endoplasmic reticulum is known as the __________ space or, ___________

cisternal ; lumen

The fibrous protein, ____________, found in the extracellular matrix of animal cells, is also a major component of cartilage and tendons.

collagen

The inner folded membrane of the mitochondria has numerous contiguous layers called

cristae

Due to the constant random motion of its atoms and molecules, a substance will exhibit net movement from a region where it has a higher concentration to a region where it has a lower concentration. This net movement is called

diffusion

Each membrane-spanning region of a transmembrane protein is called a transmembrane

domain

Phagocytosis is one of the three main types of

endocytosis

Based on the direction of movement, bulk transport can be divided into two main categories: ___________ and ____________.

endocytosis ; exocytosis

Eukaryotic cells achieve compartmentalization through an extensive _______________ system that weaves through the interior of the cell and by numerous membrane-bound ______________ that form compartments where biochemical processes can occur independently.

endomembrane ; organelles

Scientists have proposed that chloroplasts and mitochondria arose by a process called ____________, in which a smaller cell comes to live inside a larger cell.

endosymbiosis

Lipid synthesis occurs with the help of

enzymes embedded in the smooth ER.

In order to survive, grow, and reproduce, a cell must

exchange materials and information with its environment

The fusion of a secretory vesicle with the plasma membrane in order to discharge the contents of the vesicle is called

exocytosis

The reverse of endocytosis is

exocytosis

The long, threadlike structures protruding from the surface of bacteria are called

flagella

Cells continually exchange materials and information with their environment. This exchange is crucial

for all the processes occurring in a cell

Kary refers to the

genetic material

An aqueous solution with a lower concentration of solutes will have a ___________________ concentration of free water molecules.

higher

Passive transport occurs only when there is a concentration gradient and molecules/ions move from the side of the membrane with

higher concentration to the side with lower concentration.

Water is attracted to charged or polar solutes, forming ________ shells around them.

hydration

Water is attracted to charged or polar solutes, forming ___________ shells around them.

hydration

The space between the two membranes of a mitochondrion is known as the ________________ space

intermembrane

If two solutions have the same concentration of solutes (all solutes), they are __________ solutions.

isotonic or isosmotic

The lack of double bonds in phospholipids with saturated fatty acids allow them to pack together tightly, and therefore the membrane is _______________ fluid. Kinks introduced by double bonds in lipids with unsaturated fatty acids prevent them from packing together tightly, and therefore the membrane is ___________ fluid.

less ; more

The digestion of substances taken into the cell and the breakdown of old organelles in the cell are both performed by organelles called

lysosomes

Where does degradative enzymes destroy particles that the cell has ingested occur?

lysosomes.

Because of the kinks in chains fatty acids, phospholipids with unsaturated fatty acids tend to

make the membrane more fluid.

Surface ____________ give cells their identity. In multicellular organisms, this allows the recognition of cells that are of the same tissue type.

markers, lipids, glycolipids, or proteins

Cellular ___________ are said to be selectively _____________ because they allow some substances to pass through easily while other substances pass through very slowly or not at all.

membranes ; permeable

Centrosomes, also called _____________ -organizing centers, are important for cell division in animals.

microtubule

The organelles that are both surrounded by a double membrane, have their own DNA, are involved in energy metabolism, and have their own protein synthesis machinery are the ___________ and __________

mitochondria/mitochondrion ; chloroplasts

Golgi functions in

modifying and sorting proteins to their correct target destination

Myosin functions as a

motor protein to move cargo along actin filaments

The diffusion of water across a selectively permeable membrane is called

osmosis

Exocytosis is the bulk transport of substances

out of the cell.

Transport that occurs without a cell expending any of its own energy is called __________ transport.

passive

Most bacterial cells are encased by a strong cell wall composed of________________ which is a carbohydrate matrix cross-linked by polypeptides.

peptidoglycan ; murein

Functions that include glycoprotein production and protein sorting are characteristic of the _________ endoplasmic reticulum.

rough

During facilitated diffusion by carrier proteins, when solute concentrations are low, increasing the solute concentration causes a linear increase in the rate of diffusion. However, at high solute concentrations, further increases in the solute concentration no longer increase the rate of diffusion. This means that carrier proteins exhibit

saturation

In addition to storing lipids for energy metabolism, lipid droplets can act as

secondary sites of lipid synthesis

A partially permeable membrane would allow similar molecules to pass through without discriminating between them. Because the cell uses proteins to transport molecules through the membrane and those proteins only transport specific molecules, the membrane is said to be

selective.

Plasma membranes allow some substances to pass through easily while other substances only pass through very slowly or not at all. For that reason, plasma membranes are said to be

selectively permeable

Functions that include steroid synthesis and assembly of membrane lipids are characteristic of the _________ endoplasmic reticulum

smooth

Ca2+ ions are stored in the __________ endoplasmic ___________

smooth ; reticulum

The sodium-potassium pump actively pumps

sodium ions out of the cell and potassium ions into the cell

When 10 grams of NaCl are dissolved in 1 L of water, NaCl is called the ____________ and water is called the ____________.

solute ; solvent

Although a eukaryotic cell membrane can contain many different lipids, they can be classified in three groups: glycerol phospholipids, _____________ , and ______________.

sphingolipids ; sterols

Although a eukaryotic cell membrane can contain many different lipids, they can be classified in three groups: glycerol phospholipids, ________________ , and _______________.

sphingolipids ; sterols

Carrier proteins that transport 2 different types of molecules or ions may be either ___________ or antiporters.

symporters

Where does proteins are modified before being transported to other locations occur

the Golgi apparatus.

Oxygen is a small non-polar molecule and can diffuse into the cell without the need for a transport protein. Oxygen-binding proteins like hemoglobin do not

transport oxygen across the membrane. They increase the effective concentration of oxygen (which has a very low solubility).

microtubules are made of

tubulin, and they are essential in chromosome movement during mitosis. Microtubules are big

The central _________ of a plant cell is involved in maintaining the tonicity of the cell

vacuole

In an aqueous solution the solvent is

water

Osmosis occurs when there is a selectively permeable membrane and it refers to the diffusion of

water

The cytoplasm contains ions and molecules dissolved in

water

The most abundant molecule in the cytoplasm is the ______________ molecule.

water

When 10 grams of sugar are dissolved in 1 L of water, __________ is the solvent and _____________ is the solute.

water ; sugar