Chapter 3: Cells Flashcards
1
Q
plasma membrane
A
- defines boundaries of the cell
- regulates passage of substances in and out of cell
- consists of phospholipids, cholesterol, and protein
- selectively permeable
2
Q
phospholipids
A
- have hydrophilic heads
- have twin hydrophobic tails
- position themselves in a bilayer
3
Q
selective permeability
A
allows some substances to pass through easily, but not others
4
Q
nucleus
A
- cell’s control center
- contains genetic information
5
Q
nuclear envelope
A
double-layered membrane surrounding the nucleus
6
Q
nucelar pores
A
- perforate the nuclear envelope
- regulate the passage of molecules in and out of the nucleus
7
Q
nucleolus
A
- center of the nucleus
- manufactures components of ribosomes
8
Q
chromatin
A
- thread-like structures
- composed of DNA and protein
- throughout the nucleoplasm
9
Q
organelles
A
- “little organs”
- perform specific tasks in cellular metabolism
10
Q
endoplasmic reticulum (ER)
A
- network of membranous tubules within the cytoplasm of a cell
- rough ER has ribosomes on the surface
- proteins synthesized by the ribosomes move through the ER’s canals toward the Golgi apparatus
11
Q
ribosomes
A
granules of protein and RNA attached to the ER and scattered throughout the cell
12
Q
Golgi apparatus
A
- prepares proteins and packages them for export to other parts of the body
- the “post office” of the cell
13
Q
centrioles
A
bundles of microtubules that aid in cell division
14
Q
lysosomes
A
- membranous vesicles that contain enzymes that help break down protein the cell doesn’t need
- the “garbage disposal” of the cell
- form from pinched off pieces of the Golgi apparatus
15
Q
mitochondria
A
- the powerhouse of the cell
- converts organic compounds into ATP
16
Q
cytoskeleton
A
- supporting framework of the cell
- determines the shape of the cell
17
Q
microvilli
A
- folds of the cell membrane that greatly increase surface area of the cell
- can increase the cell’s absorptive area by as much as 40x
- often found in cells responsible for absorbing nutrients
18
Q
cilia
A
- hair-like processes on the surface of the cell
- move in waves of the same direction
- occur mostly in the respiratory tract and in fallopian tubes
- help move mucus and foreign particles out of the lungs
- help propel an egg cell or or embryo toward the uterus
19
Q
flagella
A
tail of a sperm cell
20
Q
passive transport
A
- movement of ions and other substances across cell membranes without the need of energy
- diffusion, osmosis, filtration, and facilitated diffusion