Section 2: Cells Flashcards
These membrane proteins are loosely attached to one side/surface of the membrane
Peripheral membrane proteins
This type of membrane protein embeds inside membranes
Integral membrane proteins
This type of membrane proteins goes all the way through the membrane, it’s on both sides of the membrane
Transmembrane integral proteins
What type of molecules can freely pass across the membrane?
Everything else requires…
Small, uncharged, nonpolar molecules
Transport proteins
PERIPHERAL membrane proteins are generally HYDROPHILIC/HYDROPHOBIC
What holds them in place?
How can they be disrupted or detached?
hydrophilic
H-bonding, electrostatic interaction
Changing salt concentration or pH
Integral membrane proteins are generally HYDROPHILIC/HYDROPHOBIC?
What can destroy and expose them?
Hydrophobic
Detergent
In cells, these proteins provide passageway through membrane for hydrophilic (water-soluble) substances (polar, and charged
Channel Proteins
These proteins distinguish between self and foreign
What type of molecule are they? What is attached to them?
What is an example of a recognition protein on macrophages?
Recognition proteins
glycoproteins
Oligosaccharides
Major-histocompatibility complex (MHC)
These proteins allow the passage of ions across the cell membrane that respond to stimuli.
What are they called in nerve and muscle cells?
Ion channels
Gated channels
These are ion channels that respond to differences in membrane potential
Voltage gated ion channels
These are ion channels where a chemical binds and opens the channel
Ligand gated ion channels
These are ion channels that respond to pressure, vibration, or temperature differences
Mechanically gated ion channels
In cells, these proteins allow the passage of certains ions + small polar molecules
Do they tend to be specific or unspecific?
Porins
Specific. If you can’t fit you don’t go through
This type of porin increases the rate of H2O passing in kidney and plant root cells.
Aquaporin
These proteins bind to specific molecules, causing a shape change in the proteins (still bound to the molecule) so that the molecule can pass across.
They seem to be specific to movement across membrane via ____________
Ex: glucose going into the cell.
Carrier Proteins
Integral membrane proteins
Some of these proteins use ATP to transport materials across the cell membrane. Not all do however.
Transport proteins
Transport proteins that use ATP employ this type of transport
What is an example of active transport in cells?
What type of transport is it when transport proteins don’t use active transport
Active Transport
Na+ and K+ pump to maintain the electrochemical gradient
Facilitated diffusion
These proteins attach to neighboring cells and provide anchors for internal filaments and tubules which provide stability
Adhesion proteins
These proteins are the binding site for hormones and other trigger molecules
Receptor proteins
This lipid molecule of the cell adds rigidity to the membrane of animal cells under normal conditions, but at a low temperature maintains its fluidity
What is the similar molecule in plants?
Cholesterol
Sterols
Do prokaryotes have cholesterol in their membranes?
What do they have?
No.
Hopanoids
This is a carbohydrate coating that covers the outer face of the cell wall of some bacteria and the outer face of the plasma membrane.
What is it made of?
What does it provide?
Glyocalyx
Glycolipids (attached to plasma membrane) and glycoproteins (like recognition proteins)
Barrier to adhesive capabilities of pathogens or markers for cell recognition
This organelle contains chromatin, chromosome, histones, nucleosomes, etc.
Nucleus
This is the name for DNA when it is not condensed
Chromatin
This is the term for condensed chromatin when the cell is ready to divide
Chromosome
These proteins organize DNA which coils around them to into bundle nucleosomes
Histones
This is the basic unit of DNA packaging in eukaryotes, consisting of a segment of DNA wound in sequence around eight histone protein core
nucleosome
These are found inside the nucleus and are the maker of ribosomes, aka…..
Nucleolus, makes ribosomes AKA rRNA
rRNA synthesized in the nucleolus + ribsomal proteins imported from the cytoplasm =?
Ribosomal subunits
After ribosomal subunits form in the nucleolus, where are they exported for final assembly into a complete ribosome?
The cytoplasm
The nucleus is bound by a SINGLE/DOUBLE layer nuclear envelope
Double layer
What are in the nuclear envelope which allow for transport?
What transports out of them?
Nuclear Pores
mRNA, ribosome subunits, dNTPs, proteins like RNA polyermase, histones, etc.
Is there a cytoplasm in the nucleus?
What is the term then for the similar area in the nucleus?
No
Nucleoplasm
This is a dense fibrillar network inside the nucleus of ______ cells made of intermediate filaments and membrane associated proteins.
It provides mechanical support and helps regulate DNA replication cell division, and chromatin organization
Nuclear Lamina, Eukaryotic cells
This in an irregular shaped region within the cell of a PROKARYOTE that contains almost all genetic material
Nucleoid (similar to nucleus in eukaryotes)
Is the nucleoid membrane bound?
No, by the nucleus in eukaryotic cells is
Metabolic activity and transport occur here. It doesn’t include the nucleus but does include cytosol, organelles, everything suspended within it except the nucleus
Cytoplasm (NOT a structure, just an area)
This is the term for streaming movement within the cell in the cytoplasm
Cyclosis
The are made of RNA + protein, they function to make proteins
Ribosomes
These cells have a 60S + 40S = 80S ribsome
Eukaryotes
These cells have a 50S + 30S = 70S ribosome
Prokaryotes
In ribosome formation, the two subunits produced inside the nucleolus move into the cytosplasm where they are assembled into ___S ribosomes (EUKARYOTES)
80S
This creates glycoproteins by attaching polysaccharides to polypeptides as they are assmebled by ribosomes
Rough Endoplasmic Reticulum
In eukaryotes, the rough ER is continuous with the…
Outer membrane
This organelle synthesizes lipids and steroid hormones for export
Smooth Endoplasmic Reticulum (no ribosomes)
In liver cells, the __________ has functions in breakdown of toxins, drugs, and toxic by products from cellular reactions. It can also store ions
Smooth ER
These are vesicles that contain digestive enzymes, functioning in apoptosis by releasing its contents into the cell
Lysosomes
Where are lysosomes produced?
The digestive enzymes within them require a LOW/HIGH pH?
The Golgi apparatus
low pH, so they any that escape remain inactive in the neutral pH of the cytosol.
Are there lysosomes in the plant cell?
Maybe. But generally thought of as none.
These organelles break down substances like fatty acids, and amino acids. It can create or break down hydrogen peroxide.
Where are they common in mammals, where they break down toxins?
Peroxisomes
Common in the liver and kidney
This is the term for the cytoplasm without the organelles, it’s the jell-O like substance
Cytosol
What function do peroxisomes have in plant cells?
They modify by-products of photorespiration
What are the peroxisome like structures in germinating seeds which break down stored fatty acids to help generate energy for growth?
Glyoxysomes
This substance can be produced by peroxisomes which can be used to oxidize substrates. It can also be broken down by peroxisomes
Hydrogen peroxide
These provide support and motility for cellular activities, they are the spindle apparatus which guide chromosomes during cell division.
Microtubules
What do microtubules compose, other than the spindle apparatus which guides chromosomes?
What protein are microtubules composed of?
Flagella and cilia
Tubulin
These provide support for maintaining cell shape
Intermiediate filaments
These are made up of actin and are involved in cell motility, like in skeletal muscle amoeba pseudopod, cleavage furrow
Microfilatments
These are made of microtubules, 9+2 array, 9 pairs + 2 singlets in center
Flagella and cilia
These include centrioles and basal bodies, is a structure found in eukaryotic cells from which microtubules emerge.
9x3 array
Microtubule organizing centers
These have two main functions: the organization of eukaryotic flagella and cilia and the organization of the mitotic and meiotic spindle apparatus, which separate the chromosomes during cell division.
Microtubule organizing center
These are MTOCS that are at the base of each flagellum and cilium and organize their development, are a 9x3 array
Centrosomes and basal bodies
Plant cells lack centrioles because its division is by _______ instead
of cleavage furrow – note that plants DO have MTOC’s
Cell plate
These move materials between organelles or between organelles and the plasma membrane
Tranport vacuoles
These are temporary recepticles of nutrients, they merge with lysosomes which break down food
Food vacuoles
There are large and occupy most of the plant cell interior. They exert turgor when fully filled to maintain rigidity
Central vacuoles
In addition to maintaining turgidity, these also store nutrients, and carry out functions performed by _____ in animal cells
Central vacuoles
Lysosomes
What is the name for the specialized membrane of central vacuoles?
Tonoplast
These are in plants and store starch, pigments, and toxic substances like nicotene
Storage vacuoles
These are in single celled organisms, they collect and pump excess water out of the cells to prevent bursting
What type of transport is it?
In what organisms are they found?
Are they in hypertonic or hypotonic environment
Contractile vacuoles
Active Transport
Protista (ameoba, paramecia)
Hypotonic (less concentration of solutes inside the cell, hence these push water out of the cell to maintain hypotonicity)
Cell walls are found in these 4 organisms
Plants, fungi, protists, and bacteria
This forms the cell wall in plants
This forms it in fungi
This forms it in bacteria
This forms it in archea
Cellulose
Chitin
peptidoglycan
polysaccharides
This structure provides support in plants, fungi, protists, and bacteria. Sometimes a secondary one develop beneath the primary one
Cell wall
This is found in animals in the area between adjacent cells beyond the plasma membrane and glycocalyx. It provides mechanical support and helps bind adjacent cells
Extracellular matrix
What occupies the extracellular matrix?
What is most abundant protein in the extracellular matrix?
Fibrous structural proteins, adhesion proteins, and polysaccharides secreted by cells
Collagen
Integrin and fibronectin are also seen
These are found in plant cells, include chloroplasts, leucoplasts, and chromoplasts
Plastids
These are the site of photosynthesis in plant cells
Chloroplasts
These plastids store starch in plant cells
Leucoplasts
These plastids store carotenoids in plant cells
Chromoplasts
This is the site of ATP production,
What else does it perform?
Mitochondria
Fatty acid catabolism (β-oxidation)
Where are fatty acids made?
Cytosol
The mitochondira has its own ________ and _________ and a SINGLE/DOUBLE layered membrane
Circular DNA
Ribosomes
Mitchondria give rise to what theory base upon having its own circular DNA and ribosome?
Endosymbiotic theory
This structure is made of microtubules (cilia and flagella), microfilaments, intermediate filaments. In eukaryotic cells it aids in cell division, cell crawling, and the movement of the cytoplasm and organelles
Cytoskeleton
Is the normal state of plant cells hypertonic or hypotonic?
Hypotonic
In plant cells, the vacuole swells in hypotonic solution leading to…
In an isotonic solution, the cell is
In a hypertonic solution, the cell is
turgidity
Flaccid
Plasmolyzed
This occurs in hypertonic solutions in plant cells, the cytoplasm is pulled away from the cell wall
Plasmolyzed
Fungal, in addition to plant cells, will remain turgid in hypertonic solutions due to ______
In an animal cell, it will undergo
Cell walls
Cytolysis (bursting)
This is the network of organelles and structures, either directly or indirectly connected, that function in the transport of proteins and other
macromolecules into or out of the cell.
Endomembrane system
What organelles comprise the endomembrane system?
Plasma membrane, endoplasmic reticulum, golgi apparatus, nuclear envelope, lysosomes, vacuoles, vesicles,
endosomes but not the mitochondria or chloroplasts
In this category of circulation, Brownian movement, cyclosis, and movement through the ER occur
Intracellular Circulation
In intracellular circulation, this type of movement occurs when particles move due to kinetic energy, it spreads small suspended particles throughout the cytoplasm
Brownian Movement
This type of intracellular circulation is the circular motion of the cytoplasm around cell transport molecules
Cyclosis/Streaming
In intracellular circulation, this structure provides a channel through the cytoplasm and provides a direct and continuous pathway from the plasma membrane to the nuclear membrane
Endoplasmic Reticulum
What are the two categories of extracellular circulation?
Diffusion and the circulatory system
In extracellular circulation, this occurs when cells in close contact with external environment can suffice for food and respiration needs. It is also used for the transport of materials between cells and interstatial fluid around cells in more complex animals
Diffusion
This type of extracellular circulation occurs in complex animals with cells too far from the external environment, it uses vessels
Circulatory System
These are keratin filaments inside cells, they attach to adhesion plaques that bind adjacent cells together. They are found in tissues with mechanical stress
They are found in PLANT/ANIMAL cells
Desmosomes
Skin epithelium, cervix/uterus are where they are commonly found
Animals
Desmosomes form _____ between cells
Tight Junctions
These completely encircle each cell, producing a seal that prevents the passage of materials BETWEEN cells
Tight Junctions
Tight junctions are characteristic of cell lining the _______ where materials are required to pass through cells into blood.
Digestive tract.
These force all materials to enter cells, keeping ions and molecules out of the space between the cells
What two ways can molecules enter the cells?
Tight junctions
Active Transport of Diffusion
Tight junctions are found in PLANT/ANIMALS cells
Animal cells
These are narrow tunnels between animal cells (connexins), they prevent the cytoplasms of each cell from mixing but allow the passage of ions and small molecules.
Gap Junctions
These are essentially channel proteins of two adjacent cells that are closely aligned, tissues like heart have these to pass electrical impulses
Gap Junctions
These are narrow tunnels between plant cells
Plasmodesmata
This category of organisms includes all organisms except for bacteria, cyanobacteria, and archaebacteria
Eukaryotes
EUKARYOTES/PROKARYOTES have a plasma membrane
Prokaryotes
Do prokaryotes have a ribosome?
Yes
Do prokaryotes have DNA?
yes, a single circular DNA molecule
Do prokaryotes have a cell wall?
Yes, not eukaryotes
Do prokaryotes have a nucleus?
No, nucleoid
What is the composition of the ribosome of prokaryotes?
50S +30S = 70S
Are flagella constructed from microtubules in prokaryotes?
No.
This is defined as higher solute concentration within cells than the surrounding environment
Hypertonic
This is defined as a lower solute concentration within cells than the surrounding environment
Hypotonic
This is defined as equal solute concentration within the cell and outside the environment
Isotonic
This is the collective movement of substances in the same direction in response to a force or pressure
Bulk Flow
Simple diffusion, osmosis, dialysis, plasmolysis, facilitated diffusion, countercurrent exchange are all what type of transport?
Passive transport
This type of passive transport is defined as the diffusion of different solutes across a selectively permeable membrane
Dialysis
This type of passive transport is defined as the movement of water out of a cell that results in its collapse
Plasmolysiis
This type of passive transport is defined as diffusion by bulk flow in opposite directions; like blood and water in fish gills
Countercurrent Exchange
Do all particles move with the gradient in diffusion?
No, we speak of net diffusion. Some particles still move against the gradient
This type of transport is the movement of particles against their concentration gradient that requires energy. It is usually SOLUTES like small ions, amino acids, and monosaccharides
Active transport
This is cytosis that uses ATP
Endocytosis
This is cytosis in which undissolved material (solid) enter a cell, the white blood cell engulfs. The plasma membrane wraps outward around it.
Phagocytosis
This is cytosis of dissolved material (liquid), the plasma membrane invaginates (infolds)
Pinocytosis (like formation of endosome)
This cytosis is where specific molecules bind to receptors, proteins that transport cholesterol in blood (LDL) and hormones target specific cells by this.
Receptor Mediated Cytosis
Receptor mediated cytosis is a form of _____
Pinocytosis
