Cell anatomy and physiology Flashcards
What substances are transported by bulk-end endocytosis?
solutes in extracellular fluid
Structure and function
lysosomes
fuses with and digest contents of vesicles, endosomes, and phagosomes formed during bulk-phase endocytosis and transports final products of digestion into cytosol; digests worn out organelles (autophagy), entire cells (autolysis), and extracellular materials.
what substances are transported via transcytosis?
antibodies across endothelial cells
a common route for substances to pass between blood plasma and interstitial fluid.
what substances are transported via exocytosis
neurotransmitters, hormones, and digestive enzymes
Define vesicle transport
active process in which substances move into or out of cells in vesicles that bud from the plasma membrane and requires energy from ATP.
What are the two types of cell membrane proteins?
integral or transmembrane
peripheral
What substances are transported by osmosis?
H2O
What substances are transported via facilatated diffusion?
polar solutes such as glucose, K+, Cl-, Na+, and CA2+.
Definition and function of cillia and flagella
cilia: hairy-like projections that move substances and fluid across the top of the cell
flagella: flexible projections from the cell that moves the entire cell (sperm)
Define bulk-phase endocytosis
“cell drinking”; the movement of extracellular fluid into a cell by infolding of plasma membrane to form a vesicle.
Structure and function
peroxisomes
oxidizes amino acids and fatty acids
detoxifies harmful substances like free radicals
define transcytosis
movement of a substance through a cell as a result of endocytosis on one side and exocytosis on the opposite side.
Structure and function
smooth endoplasmic reticulum
synthesizes fatty acids and steroids
stores and releases calcium ions in muscle cells
define primary active transport
an active process in which a substance moves across the membrane against its concentration gradient by pumps that use energy supplies by hydrolysis of ATP.
What substances are transported through simple diffusion?
nonpolar hydrophobic solutes such as oxygen, CO2, fatty acids, and steriods. polar molecules such as water, urea, and small alcohols.
What are the 5 types of vesicle transport?
Receptor-mediated endocytosis
phagocytosis
bulk-phase endocytosis
exocytosis
transcytosis
Structure and function
mitochondria
ATP production via aerobic cellular respiration and plays an early role in cell death
Structure and function
nucleus
nuclear pore control movement of substances between nucleus and cytoplasm
houses nucleolus which produce ribosomes
and genetic information in the form of chromosomes which control cellular structure and function
define channel mediated facilitated diffusion
Channel proteins span the membrane and make hydrophilic tunnels across it, allowing their target molecules to pass through by diffusion. Channels are very selective and will accept only one type of molecule (or a few closely related molecules) for transport. Passage through a channel protein allows polar and charged compounds to avoid the hydrophobic core of the plasma membrane, which would otherwise slow or block their entry into the cell.
What substances are brought in (symport) and which are brought out (antiport)?
Antiporters move Na+ or H+ and another substance in opposite directions across the membrane (one in one out)
Symporters move Na+ or H+ and another substance in the same direction across the membrane (two in or two out)
In: glucose, amino acids
out: ca2+ and H+
Definition and function of cytoskeleton
a microscopic network of protein filaments and tubules in the cytoplasm of many living cells, giving them shape and coherence.
Structure and function
nuclear envelope
The nuclear envelope has many nuclear pores that allow materials to move between the cytosol and the nucleus. Intermediate filament proteins called lamins form a structure called the nuclear lamina on the inner aspect of the inner nuclear membrane and give structural support to the nucleus.
Structure and function
centrioles
The main function of centrioles is to produce cilia during interphase and the aster and the spindle during cell division.
Structure and function
cytosol
fluid in which cell’s metabolic reactions occur
Structure and function
rough endoplasmic reticulum
synthesizes glycoproteins and phospholipids
Structure and function
cytoplasm
site of all intercellular activies
holds organelles
Structure and function
plasma/cell membrane
protects cellular contents
mediates entry and exit of substances
Structure and function
ribosomes
protein synthesis
Structure and function
golgi complex
sorting, transporting, and packaging proteins
Structure and function
centrosome
Organizing changes to the shape of the cell membrane that allow the membrane to “pinch” in two during cell division.
Ensuring that chromosomes are properly distributed to daughter cells by creating and shortening mitotic spindle fibers.
Overseeing other important changes to cell membrane shape, such as those seen in phagocytosis.
Structure and function
chromatin
package long DNA molecules into more compact, denser structures. This prevents the strands from becoming tangled and also plays important role in reinforcing the DNA during cell division, preventing DNA damage, and regulating gene expression and DNA replication.
