Cells and Organelles Flashcards
What happens to products that are destined for secretion from the Golgi apparatus?
Travel in vesicles that empty into the extracellular environment (exocytosis)
secretion products must accumulate within the Golgi before secretion, these products include proteins and hormones
In which type of cell are vacuoles found?
within all plant and fungal cells
Some animal and protist cells
Rarely in bacterial cells
What proteins and molecules are utilized by facilitated transport?
large, hydrophilic molecules that cannot directly travel across the belayer utilize Integral proteins
What is the extracellular matrix composed of?
Carbohydrates
Extensive network of fibrous structural proteins
Adhesion proteins
Glycocalyx:
A carbohydrate coat consisting of glycoproteins and glycolipids that covers the cell membrane of some animal cells and the outer face of the cell wall of some bacteria
What are the functions of glycocalyx?
Anchors to the exterior of the cell and can provide: adhesive capabilities for potential cell invaders, protective barrier to infection and can act as a marker for cell-to-cell recognition
Functions of central vacuole
Act as storage vacuoles for starches, pigments and toxic substances
Contains specialized membrane called tonoplast which helps maintaining cell rigidity by exerting turgor
Cytoplasmic streaming
Transports proteins, nutrients, and organelles throughout the cell in a organized manner
What is the array arrangement of each cilium and flagellum in microtubules?
9 + 2 array
An outer ring of 9 microtubule doubles, and two singles at the center
Passive diffusion
Molecules diffuse from a higher concentration to a lower concentration
Does not require energy
Molecules can diffuse through channel proteins
When proteins are used to aid in passive diffusion, it is known as _________________ diffusion.
Facilitated
What cells contain chloroplast?
select eukaryotic cells like plant cells and some protist like algae
NOT PRESENT in animal, fungal and prokaryotic cells
What are the functions of the nuclear lamina?
- Primary role is to provide structural (mechanical) support to the nucleus
- Regulates DNA organization, DNA replication and cell division and chromatin organization
Nuclear lamina
Dense, fibrous network of proteins associated with the inner membrane of the nuclear envelope
intermediate filaments + membrane associated proteins
Keratin
Protein concentrated in the skin, hair, and nails
Most common type of intermediate filament protein
Proteins used in passive diffusion
Porins: allow any hydrophilic molecule (that fits) pass through
Ion channels: allow ions (like calcium) pass through, down their concentration gradient
Glycosylation
A carbohydrate is attached to the protein which will then move toward the Golgi for packing, a common manipulation of proteins that enter the rough ER lumen
Functions of the lysosome
- vesicles produced by the golgi
- Contain hydrolytic/ digestive enzymes (that function at low pH) that can hydrolyze substances taken up by the cell via endocytosis to break down nutrients, bacteria, and other cellular debris
- Can break down a cell’s unneeded/defective components by a process called autophagy
- Can also contribute to apoptosis (programmed cell death) when they release their contents into the cell
Cytosis
Processes cells use to facilitate the bulk transport of large, polar (hydrophilic) molecules against their concentration gradient
active transport mechanism
What are the two main types of integral proteins involved in facilitated transport?
Channel proteins: serve as an open tunnel on both sides of the bilateral
and carrier proteins: allows molecules to bind to one side, then changes shape to bring the molecule to the other side
Where are anchoring junctions found?
In tissue that experience heavy mechanical stress
Ex: skin epithelium, cervix, uterus
Desmosomes
anchoring junction the provides mechanical stability to tissue by anchoring cells to each other via intermediate filaments
”staples”