Biology 168
what is the function of chloroplast
- cover light energy to chemical energy - perform photosynthesis
how are materials delivered to lysosomes?
- phagocytosis -autophagy - receptor:mediated endocytosis(the process of the cell membrane can pinch off a vesicle/to bring outside material into the cell/ a third type of endocytosis is pinocytosis; it brings fluid into the cell)
give a list of tasks performed by bacterial organelles
- storing calcium ions or other key molecules - holding crystals of the mineral magnetite
list several things about the nucleus structure
- surrounded by a double membrane nuclear envelope - the nuclear envelope is studded with pore-like openings - the inside surface is linked to fibrous proteins - the nucleus has a distinct region called the nucleolus
Mitochondria have two membranes. Describe both
- the inner one is folded into a series of sac-like cristae -the solution inside the cristae is the mitochondrial core function
list some things about the structure of ribosomes
- they are non-membranous thus are not considered organelles - they have large and a small subunit - both contain RNA molecules - can both be attached to the rough ER - can be free in the cytosol, the fluid part of the cytoplasm
when are proteins packaged into vesicles?
- when they move from the RER to the golgi apparatus - when the golgi apparatus to the cell surface
describe the cytoskeleton structure
-composed of protein fibers -gives the cell shape and structural stability
what does the secretary pathway propose?
-proteins intended for secretion from the cell are synthesized - they are processed in a highly prescribed set of steps
list some facts about eukaryotes
-range in size from very small to very large (microscpic algae to 100-meter tall redwood trees) -many are multicellular (occasional unicellular) - most eukaryotic cells are larger than most prokaryotic cells
describe the mitochondria
-they have their own DNA - they manufacture their own ribosomes
Name three domains and tell whether they are prokaryotic or eukaryotic
1. Bacteria: pro 2. Archaea: neither 3. Eukarya: euk
Name and describe four things all cells have
1. Nucleic Acids: store and transmit information 2. Proteins: performs most of cells functions 3. Carbs: chemical energy, carbon, support, identity 4. Plasma Membrane: selectively permeable membrane barrier
Name and Describe the two groupings of life
1. Prokaryotes: lack a membrane-bound nucleus 2. Eukaryote: have a nucleus
there are four key differences between eukaryotic and prokaryotic cells and they have been identified as what?
1. eukaryotic chromosomes are found inside a membrane-bound compartment termed nucleus 2. eukaryotic cells are often much larger 3. eukaryotic cells contain extensive amounts of internal membrane 4. eukaryotic cells feature a diverse and dynamic cytoskeleton
Give some structural similarities of bacteria
1. plasma membrane 2. a single chromosome 3. ribosomes; which synthesize proteins 4. stiff cell wall
the compartmentalization of eukaryotic cells offers two primary advantages, what are they?
1. separation of incompatible chemical reactions 2. increasing the efficiency of chemical reactions
what is the function of the mitochondria?
ATP production is a mitochondrion's core function
Which of the following statements is true? D.) Larger cells have less volume than smaller cells. A.) As cells get larger, the volume increases more than the surface area. B.) Larger cells have less surface area than smaller cells. C.) As cells get larger, the surface area increases more than the volume.
As cells get larger, the volume increases more than the surface area.
Using concepts from Chapter 3, which statement best explains why proteins—and not RNA, DNA, carbohydrates, or lipids—are the molecules responsible for "reading" the array of molecular zip codes in cells?
Because proteins can have diverse structures and chemical properties, different proteins can "read" different zip codes by interacting specifically with them.
T or F. Cell components and structures do not correlate with their functions.
False. they do correlate with their function
Which answer most accurately summarizes the (1) structural and (2) functional properties of actin filaments, intermediate filaments, or microtubules?
Intermediate filaments: (1) many subunit types; (2) one cellular role
How are proteins transported to their correct location in the cell?
Proteins contain molecular "zip codes" that allow them to be shipped to the correct cellular compartment.
For prokaryotic cells, which statement is correct concerning how the structure of a particular cell component correlates with its function?
The cell wall is a tough, fibrous layer that protects the cell and gives it shape and rigidity.
T or F. Inside the membrane, all the contents of a cell excluding the nucleus (eukaryotes) are collectively termed the cytoplasm
True
what is the dynamic cytoskeleton?
a dense and complex network of fibers that helps maintain the cell shape by providing structural support
in the prokaryotic species the chromosome contains what?
a long strand of DNA and a few support proteins. The DNA double helix coils itself with the aid of enzymes to form a compact "supercoiled" structure.
define organelle && give two things that are contained inside an organelle
a membrane-bound compartment inside the cell 1. enzymes or structures specialized for a particular function 2. commonly found in eukaryotic cells
What three distinct elements make up the cytoskeleton in eukaryotic cells?
actin filaments, intermediate filaments, and microtubules
_______ and _______ cell walls are composed of a tough, fibrous layer that surrounds the plasma membrane
bacteria && archaeal
_____ is/are identical in structure to centrioles. A. Chromatin B. Nuclear envelopes C. Microfilaments D. Mitochondria E.Basal bodies
basal bodies
Which of the following cell structures is only found in algal and plant cells? A.) cell walls B.) a cytoskeleton C.) chloroplasts D.) Golgi apparatus
chloroplasts
The _____ is composed of DNA and protein. A. ribosome B. mitochondrion C. centriole D. chromatin E. flagellum
chromatin
ribosome
consists of RNA molecule and protein and are used for protein synthesis
how is cargo brought into the cell?
endocytosis: ("inside-cell-act") refers to - any pinching off of the plasma membrane -resulting in the uptake of material from outside the cell
some prokaryotes have a tail-like __________ on the cell surface that spin around to move the cell
flagella
give the function of of bacterial organelles
functions as a compass needle to help cells sense a magnetic field and swim in a directed way/organizing enzymes responsible for synthesizing complex carbon compounds from carbon dioxide
many species have an additional layer outside the cell wall and what is it composed of?
glycolipids
specialized peroxisomes in plants are called what?
glyoxysomes
in prokaryotic cells, where are the other structures contained?
in the cytoplasm
What does the ER signal sequence do?
it binds to a signal recognition particle (SRP) that then binds to a receptor in the ER membrane
what does the plasma membrane consist of?
it consists of a phospholipid bilayer and has proteins that either span the bilayer or attach to one side
what does the signal hypothesis predict?
it predicts proteins bound for the endomembrane system have a zip code which directs the growing polypeptide to the ER. This zip code is a 20 amino-acid-long ER signal sequence.
describe some peroxisome oxidation reactions
liver cell peroxisomes contain enzymes that remove electrons from, or oxidize, the ethanol in alcoholic beverages. Specialized peroxisomes in plants called, glyoxysomes are packed with enzymes and they oxidize fats to form a compound for energy storage
Which organelle plays a role in intracellular digestion? chloroplast A.) plasmodesma B.) Golgi apparatus C.) lysosome D.) ribosome
lysosome
The cilia and flagella of eukaryotic cells are composed of _____. A.) monofilaments B.) microtubules C.) pili D.) microfilaments E.) intermediate filaments
microtubules
Which of these are hollow rods that shape and support the cell? A. plasma membrane B. chloroplasts C. peroxisomes D.microtubules E. microfilaments
microtubules
Which of these organelles carries out cellular respiration? A. smooth endoplasmic reticulum B. mitochondrion C. nucleolus D. chromatin E. ribosomes
mitochondria
what type of chromosomes do most prokaryotic species have
most have one supercoiled chromosome in the nucleoid region of the cell
describe chloroplasts
most plant and algae cells have cholorplasts (they have a double membrane and contain their own DNA) They contain membrane-bound, flattened vesicles called thylakoids. They are stacked into piles called grant.
what are most vacuoles used for?
most vacuoles are used for storage of water and/or ions to help the cell maintain its normal volume
fimbriae
needlike projections that extend from the plasma membrane of some bacteria to promote attachment to other cells or surfaces
Ribosomal subunits are manufactured by the _____. A. smooth endoplasmic reticulum B. nucleolus C. lysosome D. peroxisome E. rough endoplasmic reticulum
nucleolus
flagella
on the cell surface that spin around to move the cell
what are internal compartments in many bacterial species referred to as?
organelles (little organs)
peroxisomes are the center of what type of reactions?
oxidation reactions
Which of these organelles produces H2O2 as a by-product? A. centrioles B. mitochondrion C. peroxisome D. flagellum E. nucleus
peroxisome
what are peroxisomes?
peroxisomes are globular organelles bound by a single membrane. They originate as buds from the ER.
The _____ is a selective barrier, regulating the passage of material into and out of the cell. A. nuclear envelope B. plasma membrane C. chloroplast D. nucleus E. lysosome
plasma membrane
Nucleus
power house of the cell that is large and highly organized
what is the function of ribosomes?
protein synthesis
in the endomembrane system, what is tightly regulated?
proteins and other large molecules
What happens in the RER lumen?
proteins are folded and glycosylated and carbs are attached to the protein
_____ are the sites of protein synthesis. A. Golgi apparatuses B. Microfilaments C. Ribosomes D. Mitochondria E. Peroxisomes
ribosomes
Which of these manufactures cellular membranes by adding membrane proteins and phospholipids to its own membrane? A. ribosomes B. lysosomes C. rough endoplasmic reticulum D. Golgi apparatus E. nucleolus
rough endoplasmic reticulum
define lysosomes
single-membrane-bound structures that contain approx 40 different digestive enzymes. Found only in animal cells
many bacteria contain plasmids, define plasmids
small, supercoiled, circular DNA, usually contain genes that help the cell adapt to unusual environmental conditions and are physically independent of the cellular chromosomes
the endomembrane system is composed of what?
smooth and rough ER and the golgi apparatus (this is the primary system for protein and lipid synthesis)
Where is calcium stored? A. smooth endoplasmic reticulum B. rough endoplasmic reticulum C. mitochondria D. microtubules E. centrioles
smooth endoplasmic reticulum
What is the solution outside of the thylakoids called?
stroma
describe the function of the cytoskeleton
the cytoskeleton organizes.... -all other organelles -cellular structures into a cohesive whole the cytoskeleton also aids in cell movement and helps transport materials within the cell
the cell wall of prokaryotes forms what
the exoskeleton
what do the fibrous proteins of the cytoskeleton do
the fibrous proteins move and change to alter
What is the function of the rough ER?
the function is synthesis of specific proteins that will be inserted into the plasma membrane, secreted to the cell exterior or shipped to an organelle
what is the function of the nucleus?
the function is to store information and process that info. It contains the cells chromosomes and ribosomal RNA synthesis (in the nucleolus)
what is the function of lysosomes
the function of lysosomes is to aid in digestion- wast processing
what is the function of the golgi apparatus
the functions include - processes, sorts, and ships proteins synthesized in the rough ER - cis side of the golgi apparatus receives products from the rough er - trans side ships them out to other organelles or the cell surface - membranous vesicles carry materials to and from the organelle
describe the golgi apparatus
the golgi app is formed by a series of stacked flat membranous sacs called cisternae. there is a distinct polarity or sidedness.
cytoskeleton
the inside of the cell is supported by a network of long, thin protein filaments
Which features are common to all cells? flagella and fimbriae the cell wall photosynthetic membranes the endoplasmic reticulum the plasma membrane chloroplasts mitochondria vacuoles the nucleus ribosomes lysosomes genetic information (DNA) in chromosomes cytoskeleton the cytoplasm
the plasma membrane, ribosomes, genetic information (DNA) in chromosomes, cytoskeleton, the cytoplasm
in eukaryotic cells, what makes it difficult for molecules to diffuse across the entire cell & how is the problem solved
the relatively large size of the eukaryotic cells ......... the problem is solved by breaking up the large cell volume into several smaller membrane-bound organelles
describe the rough ER
the rough ER is a network of membrane-bound tubes and sacs studded with ribosomes. The inside interior is called the lumen and it is continuous with the nuclear envelope
when does the sequence of events start in reference to endocytosis
the sequence begins when.... - macromolecules outside of the cell bind to receptors on the plasma membrane
Morphology
the study of the form of things
where are most proteins found in peroxisomes, mitochondria, and chloroplasts imported from?
they are mainly imported from cytosol
Which statement most accurately describes what happens to proteins that lack an ER signal sequence? A.)They bypass the ER but enter the Golgi apparatus. B.) They are released into the cytosol. C.) They are inserted into the plasma membrane. D.) They are inserted into the ER membrane but do not enter the ER lumen.
they are released into cytosol.
Molecular zip codes direct molecules to particular destinations in the cell. How are these signals read? A.)They bind to motor proteins. B.) They are glycosylated by enzymes in the Golgi apparatus. C.) They enter transport vesicles. D.) They bind to receptor proteins.
they bind to receptor proteins
since the inside surface of the nucleus is linked to fibrous proteins what does that linkage form?
they form a lattice-like sheet called the nuclear lamina
what do bacterial organelles do to generate chemical energy
they sequester enzymes to generate chemical energy from ammonium ions
What are vacuoles?
vacuoles are large, membrane-bound structures found in plants and fungi, some vacuoles are specialized for digestions. Some vacuoles contain digestive enzymes. Inside seeds, they are filled with proteins. In flower petals or fruits, they are filled with colorful pigments
exocytosis
where proteins are sent to the cell surface in vesicles that fuse with the plasma membrane to release their contents to the exterior wall