Ch 06 HW
Microtubules
Centrosomes are sites where protein dimers assemble into __________. -microtubules -microfilaments -intermediate filaments
Protein synthesis--> endoplasmic reticlum--> cis golgi cisternae--> medial golgi cisternae--> trans golgi cisternae--> plasma membrane--> --> extracellular space -As they are being synthesized, secretory proteins enter the lumen of the endoplasmic reticulum. From the ER, vesicles transport these proteins to the Golgi, where they are sequentially modified and concentrated in a cis-to-trans direction. Secretory vesicles bud from the Golgi and move along cytoskeletal filaments to eventually fuse with the plasma membrane, secreting their protein cargo. Each of these transport steps requires specialized proteins to ensure that the cargo is sent to the proper location and is able to fuse with the target membrane.
Proteins that are secreted from a eukaryotic cell must first travel through the endomembrane system. Drag the labels onto the diagram to identify the path a secretory protein follows from synthesis to secretion. Not all labels will be used. Protein synthesis--> - - - - - ---> extracellular space -cis golgi cisternae -lysosome -endoplasmis reticlum -plasma membrane -medial golgi cisternae -peroxisome -trans golgi cisternae
nucleolus -Ribosomes are manufactured by the nucleolus.
Ribosomal subunits are manufactured by the _____. -lysosome -rough endoplasmic reticulum -smooth endoplasmic reticulum -peroxisome -nucleolus
mitochondrion -Mitochondria convert the chemical energy of organic molecules to chemical energy in the form of ATP.
Which of these organelles carries out cellular respiration? -chromatin -nucleolus -smooth endoplasmic reticulum -ribosomes -mitochondrion
rough endoplasmic reticulum -The ribosomes associated with the rough ER synthesize secretory proteins bound for the exterior of the cell. Further processing and packaging occurs in the Golgi apparatus.
Which of these organelles manufactures proteins bound for secretion out of the cell? -nucleolus -Golgi apparatus -lysosomes -rough endoplasmic reticulum
Peroxisome -Peroxisomes produce hydrogen peroxide as a by-product of their metabolic processes.
Which of these organelles produces H2O2 as a by-product? -peroxisome -flagellum -centrioles -nucleus -mitochondrion
D -Microfilaments are a component of the cytoskeleton. Return to Assignment
Which of these provides the cell with structural support? -A -B -C -D -E
A -The Golgi apparatus modifies, stores, and packages products of the ER.
Which of these structures stores, modifies, and packages products? -A -B -C -D -E
lysosome -The prefix "lyso-" means decomposition.
Which organelle plays a role in intracellular digestion? -lysosome -Golgi apparatus -chloroplast -ribosome -plasmodesma
produces secretory proteins
rough er function:
rough ER →→ Golgi →→ transport vesicle →→ plasma membrane
A newly synthesized protein destined for secretion from a eukaryotic cell will generally follow which of the pathways listed below? -rough ER →→ Golgi →→ transport vesicle →→ nucleus -rough ER →→ lysosome →→ transport vesicle →→ plasma membrane -rough ER →→ Golgi →→ transport vesicle →→ plasma membrane -Golgi →→ rough ER →→ lysosome →→ transport vesicle →→ plasma membrane
-insulin -ER protein, -lysomal enzyme -Most proteins that function in the cytosol (such as actin) or in the nucleus (such as DNA polymerase) are synthesized by free ribosomes. Proteins that function within the endomembrane system (such as lysosomal enzymes) or those that are destined for secretion from the cell (such as insulin) are synthesized by bound ribosomes. As a protein destined for the endomembrane system is being synthesized by a ribosome, the first amino acids in the growing polypeptide chain act as a signal sequence. That signal sequence ensures that the ribosome binds to the outer membrane of the ER and that the protein enters the ER lumen.
All proteins are synthesized by ribosomes in the cell. Some ribosomes float freely in the cytosol, while others are bound to the surface of the endoplasmic reticulum. Most proteins made by free ribosomes function in the cytosol. Proteins made by bound ribosomes either function within the endomembrane system or pass through it and are secreted from the cell. Which of the following proteins are synthesized by bound ribosomes? Select all that apply. -insulin -actin -ER protein -DNA polymerase -lysosomal enzyme -ribosomal protein
The cell cytoskeleton is a dynamic network of fibers that can be quickly dismantled and reassembled to change cell shape and the position of cell components. -Read about the dynamic nature of the cytoskeleton and the interactions between its network of fibers.
Choose the best description of the cell cytoskeleton. -The cell cytoskeleton is similar to an animal skeleton in providing rigid internal support and structure to the cell. -The cell cytoskeleton is a dynamic network of fibers that can be quickly dismantled and reassembled to change cell shape and the position of cell components. -The cell cytoskeleton serves as permanent scaffolding to anchor cell components into position within the cell cytoplasm.
C -The nucleus contains most of a cell's DNA.
Choose the letter that indicates the organelle that contains most of a cell's DNA. -A -B -C -D -E
Plant cell wall- strong, protective structure made from cellulose fibrils central vacuole- regulates cytoplasm composition, creates internal pressure, and stores cell compounds chloroplast- makes sugar by converting light energy into chemical energy mitochondria- produces chemical energy (ATP) that can power the cell golgi apparatus- modifies and packages proteins
Drag the correct description under each cell structure to identify the role it plays in the plant cell. plant cell wall, central vacuole, chloroplast, mitochondria, golgi apparatus -produces chemical energy (ATP) that can power the cell -modifies and packages proteins -regulates cytoplasm composition, creates internal pressure, and stores cell compounds, -strong, protective structure made from cellulose fibrils -makes sugar by converting light energy into chemical energy
Microfilaments
During muscle contractions, myosin motor proteins move across tracks of ________. -microtubules -microfilaments -intermediate filaments
modifies and sorts proteins
Golgi apparatus function:
The outer surface of smooth ER lacks ribosomes, whereas the outer surface of rough ER has ribosomes.
Identify the correct statement about differences between rough and smooth endoplasmic reticulum (ER). -The outer surface of smooth ER lacks ribosomes, whereas the outer surface of rough ER has ribosomes. -Smooth ER is part of the endomembrane system of the eukaryotic cell, and rough ER is not. -Rough ER consists of a network of membranous tubules and sacs called cisternae, whereas smooth ER is less complex.
ribosomes Ribosomes are involved in the manufacture of polypeptides (proteins).
In a bacterium, where are proteins synthesized? -ribosomes -nucleus -peroxisome -nucleoid region -capsule
Microtubules
In eukaryotic flagella, the fibers that slide past one another due to the activity of dynein proteins are _________. -microtubules -microfilaments -intermediate filaments
intermediate filaments
Many cell organelles, most notably the nucleus, are anchored by ____________ which are assembled from a diverse class of proteins. -microtubules -microfilaments -intermediate filaments
plant and animal cells -Nearly all eukaryotic cells, including plant and animal cells, contain mitochondria.
Mitochondria are found in __________. -animal cells and prokaryotic cells, but not plant cells -all cells -animal cells only -plant cells only -plant and animal cells
Plant cells only: cellulose cell wall, central vacuole, chloroplast Animal cells only: centriole Both:endoplasmic reticulum, Golgi apparatus, plasma membrane, nucleus, cytoskeleton, mitochondrion Plant cells and animal cells have more in common than they have differences. Nevertheless, plant cells' unique structures play important roles. Photosynthesis occurs in plant cells' chloroplasts. The plant cell's central vacuole takes up most of the space within the cell and serves a variety of functions, including storage and hydrolysis of organic compounds. Plant cell walls, which are composed primarily of cellulose, protect the cells from damage and maintain their shape. Cellulose is the most abundant organic compound on the planet.
Plant cells and animal cells share many of the same structures, but each type of cell also has unique structures. In this activity, you will indicate which cell structures are found only in plant cells, only in animal cells, or in both plant and animal cells. Drag each cell structure to the appropriate bin. If a structure is found in both plant cells and animal cells, drag it to the "both" bin. cellulose cell wall, Golgi apparatus, centriole, endoplasmic reticulum, nucleus, plasma membrane, central vacuole, mitochondrion, chloroplast, cytoskeleton
Plant and animal cells both carry out cellular respiration, producing ATP. -All plant and animal cells carry out cellular respiration in mitochondria, producing ATP.
Select the correct statement describing cellular structure or function. -Only plant cells contain chloroplasts, and only animal cells contain mitochondria. -Plant and animal cells both carry out cellular respiration, producing ATP. -Mitochondria and chloroplasts are part of the endomembrane system of the eukaryotic cell.
D -The nucleoid region contains DNA.
The DNA-containing region of this bacterial cell is indicated by the letter _____. -A -B -C -D -E
Plasma membrane -The plasma membrane regulates the passage of material into and out of the cell.
The _____ is a selective barrier, regulating the passage of material into and out of the cell. -chloroplast -nuclear envelope -nucleus -plasma membrane -lysosome
chromatin -Chromatin is composed of DNA and protein.
The _____ is composed of DNA and protein. -chromatin -centriole -ribosome -flagellum -mitochondrion
plasma membrane -The plasma membrane is selectively permeable.
The _____ is the bacterial structure that acts as a selective barrier, allowing nutrients to enter the cell and wastes to leave the cell. -plasma membrane -nucleoid region -ribosome -pili -cell wall
Structure: cellulose Plant or Animal? plant
The cellular organization and extracellular environments of plants and animals are very different. Drag the labels to their appropriate locations in the table below. Labels of Group 2 may be used more than once. A polysaccharide that is used to synthesize cell walls, which protect cells and help maintain their shape. Structure: ___________ Plant or Animal? __________ -gap junctions -tight junctions -collagen -desmosomes -plasmodesmata -cellulose
Structure: collagen Plant or Animal? animal
The cellular organization and extracellular environments of plants and animals are very different. Drag the labels to their appropriate locations in the table below. Labels of Group 2 may be used more than once. Long fibers of protein found in the extracellular matrix that provide structural support for cells Structure: ___________ Plant or Animal? __________ -gap junctions -tight junctions -collagen -desmosomes -plasmodesmata -cellulose
Structure: tight junctions Plant or Animal? animal
The cellular organization and extracellular environments of plants and animals are very different. Drag the labels to their appropriate locations in the table below. Labels of Group 2 may be used more than once. Membrane proteins that create a watertight seal between cells. Structure: ___________ Plant or Animal? __________ -gap junctions -tight junctions -collagen -desmosomes -plasmodesmata -cellulose
Structure: desmosomes Plant or Animal? animal
The cellular organization and extracellular environments of plants and animals are very different. Drag the labels to their appropriate locations in the table below. Labels of Group 2 may be used more than once. Membrane. protein complexes that strengthen the adhesion between adjacent cells, like rivets, to protect against pulling forces. Structure: desmosomes Plant or Animal? __________ -gap junctions -tight junctions -collagen -desmosomes -plasmodesmata -cellulose
Structure: plasmodesmata Plant or Animal? plant
The cellular organization and extracellular environments of plants and animals are very different. Drag the labels to their appropriate locations in the table below. Labels of Group 2 may be used more than once. Small channels between cells that are otherwise surrounded by walls; enable movement of water and solutes between cells. Structure: ___________ Plant or Animal? __________ -gap junctions -tight junctions -collagen -desmosomes -plasmodesmata -cellulose
Structure: gap junctions Plant or Animal? animal
The cellular organization and extracellular environments of plants and animals are very different. Drag the labels to their appropriate locations in the table below. Labels of Group 2 may be used more than once. Small channels that form across the plasma membranes of adjacent cells; especially important in intercellular communication. Structure: ___________ Plant or Animal? __________ -gap junctions -tight junctions -collagen -desmosomes -plasmodesmata -cellulose
Microfilaments
The extension of pseudopodia in amoeba is due to the regulated assembly and destruction of ___________. -microtubules -microfilaments -intermediate filaments
intermediate filaments
The only cytoskeletal fibers not associated with intracellular movement or whole cell locomotion are the ______________ -microtubules -microfilaments -intermediate filaments
desmosomes -The primary role of desmosomes (anchoring junctions) is to bind cells together.
The primary role of _____ is to bind animal cells together. -plasmodesmata -desmosomes -gap (communicating) junctions -tight junctions -the cytoskeleton
-They have membranous sacs called thylakoids that are surrounded by a fluid called stroma. -They contain the green pigment chlorophyll. -They are the sites of reactions that convert solar energy into chemical energy. The chloroplast and the chemical reactions associated with it are extremely important for all living things. The photosynthetic reactions are responsible for converting solar energy into chemical energy that is used not only by the cells in which photosynthesis occurs but also by other organisms. For example, all of the foods you eat can be traced back to a plant or other photosynthetic organism. Furthermore, the chloroplast and its reactions have had a profound influence on the constitution of Earth's atmosphere due to the fact that oxygen is a byproduct of photosynthesis.
The structure of a chloroplast is closely tied to its function as the site of photosynthesis. Some of the following statements are true for chloroplasts; others are true for mitochondria. Which statements are true for chloroplasts? Select the three that apply. -They have membranous sacs called thylakoids that are surrounded by a fluid called stroma. -They contain the green pigment chlorophyll. -Their matrix contains enzymes that function in cellular respiration. -They are the sites of reactions that convert solar energy into chemical energy. -Their inner membrane has infoldings called cristae. -They are the sites of reactions that convert chemical energy from food molecules to ATP.
C -The plasma membrane is selectively permeable.
The structure that regulates the passage of material into and out of this bacterial cell is indicated by the letter _____. -A -B -C -D -E
Smooth ER: poison detoxification, calcium ion storage, lipid synthesis Rough ER: protein synthesis Golgi apparatus: protein modification and sorting, cisternal maturation Lysosomes: autophagy, macromolecule digestion
The various parts of the endomembrane system serve different functions in the cell. In this activity, you will identify the roles of each part of the endomembrane system. Drag each function to the appropriate bin. Smooth ER: Rough ER: Golgi apparatus: Lysosomes: -protein synthesis -protein modification and sorting -autophagy -macromolecule digestion -poison detoxification -lipid synthesis -cisternal maturation -calcium ion storage
prokaryotic only: nucleiod eukaryotic only: lysosome, mitochondira, nucleolus both: flagella, plasma membrane, ribosomes
Two fundamental types of cells are known to exist in nature: prokaryotic cells and eukaryotic cells (like the one shown in the Tour of an Animal Cell animation). Both prokaryotic and eukaryotic cells carry out all of the processes necessary for life, but they differ in some important ways. In this activity, you will identify which cell structures are found only in prokaryotic cells, only in eukaryotic cells, or in both types of cells. Drag each cell structure to the appropriate bin. prokaryotic only: eukaryotic only: both: nucleoid, nucleolus, flagella, lysosome, ribosomes, mitochondria, plasma membrane
Protection -A bacterium's capsule has a protective role.
What is a function of a bacterium's capsule? -protection -DNA storage -protein synthesis -propulsion
Cell wall -The cell wall is a rigid supporting structure.
What name is given to the rigid structure, found outside the plasma membrane, that surrounds and supports the bacterial cell? -capsule -pili -cell wall -flagella -nucleoid region
nucleoid region -Bacteria lack a nucleus; their DNA is found in the nucleoid region.
Where is a bacterial cell's DNA found? -ribosomes -nucleus -peroxisome -nucleoid region -capsule
smooth endoplasmic reticulum -In addition to storing calcium, the smooth ER also plays a role in detoxification and lipid synthesis.
Where is calcium stored? -centrioles -microtubules -smooth endoplasmic reticulum -mitochondria -rough endoplasmic reticulum
cell fractionation to study the function of specific organelles -Cell fractionation can be used to separate different organelles to study their function separate from the rest of the cell.
Which of the following choices correctly matches a tool and its proper application? See Concept 6.1 (Page) -transmission electron microscopy (TEM) to study the surfaces of preserved cells -cell fractionation to study the function of specific organelles -transmission electron microscopy (TEM) to study the movement of organelles within a living cell -light microscopy to study the internal structure of cilia -scanning electron microscopy (SEM) to study the detailed movements of living cells
whether or not the cell is generally partitioned by internal membranes -Prokaryotic cells lack any internal membranous compartmentalization.
Which of the following clues would tell you if a cell is prokaryotic or eukaryotic? -the presence or absence of a rigid cell wall -whether or not the cell is generally partitioned by internal membranes -whether or not the cell contains DNA -the presence or absence of ribosomes -whether or not the cell carries out cellular metabolism
both contain their own DNA -Mitochondria and chloroplasts contain their own DNA and ribosomes
Which of the following is a common trait of chloroplasts and mitochondria? -both are found in plant and animal cells -both reproduce by meiosis -both contain their own DNA -both are surrounded by a single membrane -proteins for both are synthesized on ribosomes in the rough ER
microtubules -Microtubules are rods that also play a role in organelle movement.
Which of these are hollow rods that shape and support the cell? -plasma membrane -microtubules -peroxisomes -microfilaments -chloroplasts
tight junctions -Tight junctions form a barrier that prevents fluids from moving between cells.
Which of these cell junctions form a barrier to the passage of materials? -gap (communicating) junctions -keratin fibers -plasmodesmata -desmosomes (anchoring junctions) -tight junctions
E -This is the nuclear envelope.
Which of these is the double membrane that encloses the nucleus? -A -B -C -D -E
The nuclear envelope is continuous with the endoplasmic reticulum.
Which statement correctly describes the nuclear envelope of a eukaryotic cell? See Concept 6.3 (Page) -The nuclear envelope is a single membrane, consisting of a phospholipid bilayer. -Plasmadesmosomes in the nuclear envelope permit the exchange of macromolecules between the nucleus and the cytoplasm. -All of the proteins of the cell are synthesized on ribosomes bound on the nuclear envelope. -The nuclear envelope is continuous with the endoplasmic reticulum. -The outer layer of the nuclear envelope is coated with lamin.
Gap (communicating) junctions -Gap junctions allow for the passage of material between cells, thus facilitating communication between these cells.
_____ aid in the coordination of the activities of adjacent animal cells. -Keratin fibers -Tight junctions -Gap (communicating) junctions -Plasmodesmata -Desmosomes
Fimbriae enable bacterial cells to stick to a surface.
_____ are surface appendages that allow a bacterium to stick to a surface. -Fimbriae -Cell walls -Flagella -Mitochondria -Ribosomes
Ribosomes -Ribosomes are the site of protein synthesis.
_____ are the sites of protein synthesis. -Mitochondria -Peroxisomes -Microfilaments -Golgi apparatuses -Ribosomes
Basal Bodies -Basal bodies and centrioles have identical structures.
_____ is/are identical in structure to centrioles. -Microfilaments -Basal bodies-Mitochondria -Nuclear envelopes -Chromatin
Microtubules
____________ -serve as intracellular highways for transporting vesicles and organelles; they are also required for cellular locomotion via flagella and cilia.
Microfilaments
____________- are responsible for cell locomotion and the cell's structural characteristics.
Intermediate filaments
________________- are rope-like structures that anchor organelles and intercellular junctions called desmosomes. They are specialized for bearing tension.
defines cell shape
cytoskeleton function:
digests proteins
lysosomes function
generates ATP
mitochondria function:
assembles ribosomes
nucleolus function:
synthesizes lipids
smooth er function: