Cell anatomy and physiology

Question 1

What substances are transported by bulk-end endocytosis?

Answer 1

solutes in extracellular fluid

Question 2

Structure and function

Answer 2

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.

Question 3

what substances are transported via transcytosis?

Answer 3

antibodies across endothelial cells
a common route for substances to pass between blood plasma and interstitial fluid.

Question 4

what substances are transported via exocytosis

Answer 4

neurotransmitters, hormones, and digestive enzymes

Question 5

Define vesicle transport

Answer 5

active process in which substances move into or out of cells in vesicles that bud from the plasma membrane and requires energy from ATP.

Question 6

What are the two types of cell membrane proteins?

Answer 6

integral or transmembrane
peripheral

Question 7

What substances are transported by osmosis?

Answer 7

H2O

Question 8

What substances are transported via facilatated diffusion?

Answer 8

polar solutes such as glucose, K+, Cl-, Na+, and CA2+.

Question 9

Definition and function of cillia and flagella

Answer 9

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)

Question 10

Define bulk-phase endocytosis

Answer 10

“cell drinking”; the movement of extracellular fluid into a cell by infolding of plasma membrane to form a vesicle.

Question 11

Structure and function

Answer 11

peroxisomes

oxidizes amino acids and fatty acids

detoxifies harmful substances like free radicals

Question 12

define transcytosis

Answer 12

movement of a substance through a cell as a result of endocytosis on one side and exocytosis on the opposite side.

Question 13

Structure and function

Answer 13

smooth endoplasmic reticulum

synthesizes fatty acids and steroids

stores and releases calcium ions in muscle cells

Question 14

define primary active transport

Answer 14

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.

Question 15

What substances are transported through simple diffusion?

Answer 15

nonpolar hydrophobic solutes such as oxygen, CO2, fatty acids, and steriods. polar molecules such as water, urea, and small alcohols.

Question 16

What are the 5 types of vesicle transport?

Answer 16

Receptor-mediated endocytosis
phagocytosis
bulk-phase endocytosis
exocytosis
transcytosis

Question 17

Structure and function

Answer 17

mitochondria
ATP production via aerobic cellular respiration and plays an early role in cell death

Question 18

Structure and function

Answer 18

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

Question 19

define channel mediated facilitated diffusion

Answer 19

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.

Question 20

What substances are brought in (symport) and which are brought out (antiport)?

Answer 20

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+

Question 21

Definition and function of cytoskeleton

Answer 21

a microscopic network of protein filaments and tubules in the cytoplasm of many living cells, giving them shape and coherence.

Question 22

What is osmosis and is it passive or active?

Answer 22

Passive
Movement of water across a selectively permeable membrane from an area of higher to lower water concentration until equilibrium is reached.

Question 23

What type of permeable layer is the cell membrane?

Answer 23

selectively permeable

Question 24

What are the two types of gradients that are important for molecules crossing the cell membrane?

Answer 24

A concentration gradient: difference in the concentration of a chemical between one side of the plasma membrane and the other
An electrical gradient: difference in concentration of ions between one side of the plasma membrane and the other

Question 25

define exocytosis

Answer 25

movement of substances out of the cells in secretory vesicles that fuse with the plasma membrane and release their contents into the extracellular fluid

Question 26

What are the three main parts of the cell?

Answer 26

cell membrane cytoplasm (cytoplasm and organelles) nucleus (genetic material)

Question 27

What are the two types of facilitated diffusion?

Answer 27

Channel mediated facilitated diffusion Carrier mediated facilitated diffusion

Question 28

Structure and function

Answer 28

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**.

Question 29

Structure and function

Answer 29

centrioles The main function of centrioles is to produce cilia during interphase and the aster and the spindle during cell division.

Question 30

define carrier mediated facilitated diffusion

Answer 30

Carrier proteins can change their shape to move a target molecule from one side of the membrane to the other. Like channel proteins, carrier proteins are typically selective for one or a few substances. Often, they will change shape in response to binding of their target molecule, with the shape change moving the molecule to the opposite side of the membrane. The carrier proteins involved in facilitated diffusion simply provide hydrophilic molecules with a way to move down an existing concentration gradient (rather than acting as pumps).

Question 31

what substances are moved by receptor-mediated endocytosis?

Answer 31

LDLs, some vitamins, hormones, and antibodies.

Question 32

What are the three types of active processes?

Answer 32

primary transport secondary transport vesicular transport

Question 33

Structure and function

Answer 33

cytosol fluid in which cell's metabolic reactions occur

Question 34

Structure and function

Answer 34

rough endoplasmic reticulum synthesizes glycoproteins and phospholipids

Question 35

Structure and function

Answer 35

cytoplasm site of all intercellular activies holds organelles

Question 36

define receptor-mediated endocytosis

Answer 36

ligand-receptor complexes trigger infolding of a clathrin-coated pit that forms a vesicle containing ligands.

Question 37

Define active transport

Answer 37

moving substances against a concentration or electrochemical gradient, a cell must use energy.

Question 38

Structure and function

Answer 38

plasma/cell membrane protects cellular contents mediates entry and exit of substances

Question 39

Define phagocytosis

Answer 39

"cell eating"; movement of a solid particle into a cell after pseudopods engulf it to form a phagosome

Question 40

What are the 5 factors that affect simple diffusion?

Answer 40

Steepness of concentration gradient temp mass of substance diffusing surface area of diffusing surface diffusion distance (thickness of membrane)

Question 41

what type of substances are moved by primary active transport?

Answer 41

Ions such as Na+, K+, etc.

Question 42

Structure and function

Answer 42

ribosomes protein synthesis

Question 43

Structure and function

Answer 43

golgi complex sorting, transporting, and packaging proteins

Question 44

What are the two types of transport processes that move substances across the cell membrane?

Answer 44

Passive and active

Question 45

Function of proteasomes

Answer 45

Barrell-shaped structures that destroy unneeded, damaged, or faulty proteins by cutting long proteins into smaller peptides

Question 46

Structure and function

Answer 46

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.

Question 47

Define an active process and transport

Answer 47

Movement of substances against their concentration gradient which requires ATP. the transport happens in transmembrane proteins.

Question 48

What type of molecules are always permeable to the cell membrane?

Answer 48

Small, nonpolar, uncharged molecules

Question 49

Structure and function

Answer 49

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.

Question 50

What substances are moved by phagocytosis?

Answer 50

bacteria, viruses, and aged or dead cells

Question 51

Explain simple diffusion and is it passive or active?

Answer 51

passive movement of a substance down its concentration gradient through the lipid bilayer of the plasma membrane without the help of membrane transport proteins.

Question 52

define secondary active transport

Answer 52

coupled active transport of two substances across the membrane (one in and one out) using energy supplied by a Na+ or H+ concentration maintained by primary active transport pumps.

Question 53

What are the three types of passive processes?

Answer 53

Simple diffusion facilitated diffusion osmosis

Question 54

Explain facilitated diffusion and is it active or passive?

Answer 54

Passive Transmembrane proteins help solutes that are too polar or too highly charged move through the lipid bilayer