Unit 2 Chapter 7.1 & 7.2 Inside the Cell Flashcards
All cells contain which of three structures?
cell wall, plasmids, and ribsomes
chromosomes, ribosomes, plasmas, and membrane
chromosomes, cell wall, and flagella
cell wall, flagella, and ribosomes
All cells are surronded by a plasma membrane, have one or more DNA-containing chromosomes, and need ribosomes to synthesize proteins.
What is the downside to eukaryotic cells being larger?
Ions and small molecules such as adenosine triphosphate (ATP), amino acids, and nucleoties cannot diffuse across a large volume quickly.
- if the ATP that supplies the chemical energy in cells is used up on one sideof the large cell, the ATP from the other side of the cell would take a long time to diffuse to that location.
All cells have 4 things:
- Plasma membrane (Cell membrane).
- Cytoplasm
- DNA
- Organelles
Because the eukaryotic cells re subdivided, the molecules required for specific chemical reactions are often locatedwithin a give compartment or organell.
Compartmentalization offeres two key advantegs, what are they?
- Incompatibile chemical reactions can be seperated
- Chemical reactions become more efficient.
How do chemical reactions become more effecient in compartimentalization.
- substrates required for a particular recation can be be localized and maintained at high concentrations within organelles
- if subtrates have been used up, in a particular part of the organelle, they can be replaced by substrates tht have only a short distance to diffuse
- groups of enzymes tht work together can be clustered on internal membranes instead of floating free in they cytoplasm.
What are four key differences between prokaryotic and eukaryotic cells?
- Eukaryotic chromosomes are found inside a membrane bound compartment called a nucleus
- eukaryotic cells are often much larger
- eukaryotic cells contain extensive amounts of internal membrane
- eukaryotic cells feature a particularly diverse and dynamic cytoskeleton
How does the location of DNA differ between bacteria/archea and eukaryotes?
Bacteria/archea:
in nucleoid (not membrane bound); plasmids also common
Eukaryotes:
Inside nucleus (membrane bound); plasmids extremely rare
How do internal membranes and organelles differ between bacteria/archaea and eukaryotes?
bateria/archaea:
extensive internal membranes only in photosynthetic species; limited types and numbers of organelles
eukaryotes:
large number of organelles; many types of organelles
How does the cytoskeleton differ between prokaryotic and eukaryotic cells?
Prokaryotic cells are limited in extent, relative to eukaryotes
eukaryotes are extensive–usually found throughout volume of cell
How does the size differ between eukaryotic and prokaryotice cells?
prokaryotic cells are smaller
Nucleous
In eukaryotic cells, the large organelle containing the chromosomes and surrounded by a double membrane.
- function as an information storage and processing center
- amonges the largest and most highly organized of all organells
- double membrane called the nuclear envelope
Nuclear enevelope
a double membrane that encloses the nucleous
- it’s studded with pore-like openings and it’s inside surface is linked to fibrous proteins that form a lattice-lice sheet called a nuclear lamina
Nuclear lamina
a lattice-like sheet of fibrous nuclear lamins, which are one type of intermediate filaments. Lines the inner membrane of the nuclear envelope, stiffening the envelope and helping organzie the chromosomes.
Do chromosomes float freely inside the nucleous?
No, each chromosome occupy a distinct area and is attached tht he nuclear lamina in atleast one distinct location.
Nucleolus
In eukaryotic cells, specialized structure in the nucleus where ribosomal RNA processing occurs and ribosomal subunits are assembled.
- where gene products are processed
- where the RNA molecules found in robosomes are manufactured and the large and small ribosomal subunits are assembled.
The nuclear envelope is continuous with an extensive series of membrane-bound sacs called the____________ (litrally, “inside-formed-network”).
endoplasmic reticulum
rough endoplasmic reticulum (rough ER)
The portion of the endoplasmic reticulum that is dotted with ribosomes. Involved in synthesis of plasma membrane proteins, secreted proteins, and the proteins localized to the ER, Golgi apparatus, and lysosomes.
- ribosomes associted with the rought ER synthesize proteins that will be inserted intothe plasma membrane, secreted to the cell exterior, or shipped to an organelle.
- as they are being manufactured by ribosomes, these proteins move to the interiro of the sac-like component of the ER
lumen
the inerior space of any hollow structure (e.g., the rought ER) or organ (e.g., sthe stomach)
- in the lumen of the rough ER, newly manufactured proteins undergo folding and other types of processing
What are the functions of the proteins that are manufactured/produced in the rough ER?
- some carry messages to other cells
- some act as a membrane transport proteins or pumps
- some are enzymes
the common them is that the rough ER prouducts are packaged into vesicles and transported to various distant destinations, often to the surface of the cell or beyond
smooth endoplasmic reticulum (smooth ER)
the portion of the endoplasmic reticulum tht does not have ribosomes attached to it. Involved in the synthesis and secretion of lipids.
What part of the eukaryotic cell contains enzymes that catalyze reactions involving lipids?
smooth ER
What are some of the functions of the smooth ER?
- depending on the type of cell, these enzymes may synthesisize lipids needed by the organism or break down lipids that are poisonous
- it’s a manufacturing site for phospholipids used in plasma membranes
- a reservoir ofr calcium ions (Ca2+) that act as a signal triggering a whide array of activities inside the cell
Fill in the blank regarding the endoplasmic reticulum.
____________ ER has ribosomes and functions primarily as a protein-manufacturing center; _______________ ER lacks ribosomes and functions primarily as a lipid-processing center.
Rough ER; Smooth ER
The __________________ is a site of protein processing, sorting and shipping. The _______________ apparatus is a collection of flattened vesicles called cisternae.
Golgi Apparatus
Golgi apparatus
A eukaryotic organelle, consisting of stacks of flattened membranous sacs (cisternae), that functions in processing and sorting proteins and lipids destined to be secreted or directed to other organelles. Also called Golgi complex.
- stacked on top of one another
- has a distinct polarity, or sidedness
- the cis (“this side”) surface is closest to the rought ER and nucleous
- the trans (“across”) surface is oriented toward the plasma membrane.
Which side of the Golgi apparautus recieves products from the ER?
the cis side
Which side of the Golgi apparatus ships out products toward the cell surface?
the trans side
Why are mitochondria concidered cellular “power plants”?
Membrane‐bound organelles that generate cellular energy (adenosine triphosphate or ATP)
What are common features of a cells genetic materials?
• DNA‐ Stored information of
how to make all parts of cell
• Each individual piece of
information is a GENE
• DNA organized into
Chromosomes
– Linear, circular, singular, or
multiple
• Depending on the cell, may
be contained within a
membrane‐ Nucleus!
• No membrane? ‐ Nucleoid
Region
In eukaryotes, the cytoplasm consist of everything inside the plasma membranes excluding the _____________; the fluid portion of the cytoplasm is called the ________________.
nucleus;cytosol
In eukaryotes, ribosomes are not classified as organelles because ________________.
they are not surronded by a membrane.
Peroxisomes are organelles that all share a come function. What is it?
they are centers for oxidation reactions
peroxisome
an organelle found in most eukaryotic cells that contains enzymes for oxidizing fatty acids and other compounds including many toxins, rendering them harmless.
Ex: removes hydrogen peroxide (H2O2) and turns it int to H2O and O, if it didn’t the hydrogen peroxide could damage the cell
glyoxysomes
specialized typ of peroxisome found in plant cells and packed with enzymes for processing the products of photosynthesis.
In plants, ________________ are packed with enzymes that oxidize fats to form a compound that can be used to store energy for the cell.
glyoxysomes
lysosome
a small organell in an animal cell contaiting acids and enzymes that catalyze hydorlysis reactions and digest large molecuels.
Why is the lumen of a lysosome acidic?
because proton pumps in the lysosome membrane import hydrogen ions to maintain a pH of 5.0
What contains about 40 different enzymes that are each responsible for breaking up different type of macromolecules (protein, nucleic acid, lipid, or carbohydrate) into monomers.
What happens to the monomers?
lysosomes; they are then excreted or recycled.
autophagy
the process by which damaged organelles are surrounded by a membrane and delivered to a lysosome to be destroyed
What is the process of autopagy in the lysosome?
- a damaged organelle is surrounded by a membrane
- the membrane-bound organelle is delivered to a lysosome, which takes it in and begins to digest it
- small molecules from the digested organelle are recycled into the cytosol.
autophagy “same-eating”
phagocytosis
uptake by a cell of small particles or cells by pinching off the plasma membrane to form small membrane-bound vesicles
What is the process of phagocytosis in lysosomes?
- the plasma membrane detects a small cell or food particle and begins to engulf it
- the resultig membrane-bound particle is a phagosome
- the pagasome is delivered to a lysosome, which takes it in and begins to digesting it
- small molecules from the digeseted food particles are released into the cytosol.
Why is it significnt that vesicles from the Golgi apparatus fuse with endosomes?
The vesicles deliver digestive enzymes that are required for the mature lysosome to function.
Describe the structure and function of photosynthetic membranes.
photosynthetic membranes increase food production by providing a large surface area to hold the pigments and enzymes required for photosynthesis.
Describe the structure and function of organelles that contain magnetite.
the presence of a magnetic mineral, which changes position as the cell moves throught a magnetic field, allows the cell to move in a directed way.
Describe the structure and function of the cell wall.
the layer of thich, strong material sitffens the cell and provides protection from the mechanical damage.
receptor-mediated endocytosis
uptake by a cell of certain extracellular macromolecules, bound to specific receptors in the plasma membrane, by pinching off the membrane to form small membrane-bound vesicles.
early endosome
a small membrane-bound vescile, formed by endocytosis, that is an early stage in the formation of a lysosome
“inside-body”
late endosome
a membrane-bound vescile that arises from an early endosome and developes into a lysosome
After ___________________ have matured, ____________________ recieve digestive enzymes fromtheGolgi apparatus and may eventually become fully functioning lysosomes.
early endosomes;late endosomes
Regardless of how lysosomes orginate, molecules are _____________________.
hydrolyzed
endocytosis
general term for any pinching off of the plasma membrane that results in the uptake of material from outside the cell.
Includes phagocytosis, pincocytosis, and recptor-mediated endocytosis.
“inside cell-act”
pincocytosis
uptake by a cell extracellular fluid by pinching off the plasma membrane to form small membrane-bound vesicles; one type of endocytosis
“drink-cell-act”
_________________ brings fluid into the cytoplasm via tiny vesicles that from from infolding of the plasma membrane?
Pincocytosis
endomembrane system
a system of organelles in eukaryotic cells that perform most protein and lipid synthesis.
Includes the endoplasmic reticulum (ER), Golgi apparatus and lysosomes
“inner memebrane”
____________________ is the primary center for protein and lipid synthesis and processing in eukaryotic cells.
endomembrane system
vacuole
a large organelle in plant and fungal cells that usually is used for bulk storage of water, pigments, oils or other subtances.
Some vacuoles contain enzymes and have a digestive function similar to lysosomes in animals
Lysosomes are compared to _______________ in plants.
vacuoles
___________________ are the storage centers in plant and fungal cells.
Vacuoles
some contain digeesive enzymes and serve as recycling centers; most are storage containers
Why are toxins like nicotine, cocaine, and caffeine stored in vacuoles instead of the cytosol?
storing the toxins in vacuoles prevents toxins from damaging the plant’s own organelles and cells
mitochondrion
a eukaryotic organelle that is bounded by a double membrane and is the site of aerobic respiration
Where is most adenosine triphosphate (ATP) produced?
mitochondrion
cristae
sac-like invaginations of the inner membrane of a mitochondrion.
Location of the electron transport chain and ATP synthase
mitochondrial mix
central compartment of a mitochondrion, which is lined by the inner membrane; contains the enzymes and subtrates of citric acid cycle and mitochondrial DNA
What are the characteristics of mitochondria?
- posesses a small chromosome that contains genes independent of the main chromosomes in the nucleus
- manufacture their own ribosomes
- can grow and divide indpendently of nuclear division and cell division
chloroplast
a chlorophyll-containing organelle, bounded by a double membrane, in which photosynthesis occurs; dound in plants and photosynthetic protists. Also the location of amino acid, fatty acid, purine, and pyrimidine synthesis
____________ are sugar manufacturing centers in plants and algae.
chloroplasts
thylakoid
flattened, membrane-bound vesicle inside a plant chloroplast that functions in coverting light energy to chemical energy
a stack of thylakoids is a granum
Cell walls protect plans and fungi. Plants have cell walls that contain cellulose; in fungi the major structural component of the cell wall is chitin.
In plants, is the cell wall inside or outside the plasma membrane?
the cell wall is outside the cell membrane
stroma
the fluid matrix of a chloroplast in which the thylakoids are embedded
site where the Calvin cycle reaction occurs
What are some characteristics of chloroplast?
- DNA is independet of the main genetic material inside the nucleus.
- they grow and divide independently of nuclear division and cell division
In regards to the cell wall, how do they differ between plants and animals?
plants have a cell wall that provide support
animals, amoebae lack a cell wall, their exterior surface consists of just the plasma membrane
Descirbe the structure and function of the nucleus.
Membrane: has a double membrane (envelope); openings calld nuclear pores
Components: chromosomes, nucleuous, nuclear lamina
Function: genetic information, assembly of ribosome subunits, structural support
(administrative/informtion hub)
Descirbe the structure and function of the ribosomes.
Membrane: none
Components: complex of RNA and proteins
Function: protein synthesis
(Protein factory)
Descirbe the structure and function of the endomembrane system (rough ER)
Membrane: single; contains receptors for entry of the selected proteins
Components: Network of branching sacs, ribosomes associated
Function: Protein synthesis and processing
(large molecule manufacturing and shipping)
- protein synthesis & folding center
- protein finishing and shipping line
- fat factory
- waste processing and recycling center
Descirbe the structure and function of the Golgi apparatus
Membrane: single; contains receptors for products of rough ER
Components: stack of flattened cisternae
Function: Protein processing (e.g., glycosylation)
(fatty acid processing and detox center)
Descirbe the structure and function of the smooth ER
Membrane: single;contains enzymes for synthesizing phospholipids
Components: Network of branching sacs, enzymes for synthesising lipids
Function: lipid synthesis
(warehouse)
Descirbe the structure and function of the lysosomes
Membrane: single; contains protons pumps
components: acid hydrolases (catalyze hydrolysis reactions)
Function: digestion and recycling
(power station)
Descirbe the structure and function of the peroxisomes
Membrane: Single; contains transporters for selected macromolecules
Components: Enzymes that catalzye oxidation reactions, catalase (processes peroxide)
Function: Oxidation of fatty acids, ethanol, or other compounds
(food-manufactoring facility)
Descirbe the structure and function of the vacuoles
Membrane: Single; contains transporters for selected molecules
Components: varies-pigments, oils, carbohydrates, water, or toxins
Function: varies-coloration, storage of oils, carbohydrates, water or toxins
(support beams)
Descirbe the structure and function of the mitochondria
Membrane: Double; inner contains enzymes for ATP production
Components: Enzymes that catalyze oxidatin-reduction reactions, ATP synthesis
Function: ATP production
(perimeter fencing with secured gates)
Descirbe the structure and function of the chloroplast
Membrane: Double; plus membrane-bound sacs in interior
Components: pigments, enzymes that catalyze oxidation-reduction reactions, ATP synthesis
Function: production of ATP and sugars via photosynthesis
Descirbe the structure and function of the cytoskeleton.
Membrane: none
Components: actin filaments, intermediate filaments, microtubules
Function: structural support; movement of maerials; in some specices, movement of the whole cell
Descirbe the structure and function of the plasma membane
Membrane: single; contains transport and receptor proteins
Components: phospholipid bilayer with transport and receptor proteins
Function: selective permeability-maintians intracellular environment
Descirbe the structure and function of the cell wall
Membrane: none
Components: carbohydrate fibers running through carbohydrate or protein marix
Function: protection, structural support
Explain how the structure of peroxisomes and lysosomes correlate with thier function.
Both organelles contain specific sets of enzymes, and the interior of lysosomes is acidic. Peroxisomes contain catalase and other enzymes that process fatty acids and toxins via oxidation rections. Lysosomal enzymes digest macromolecuels, releasing monomers that can be recycled into new macromolecules
