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