Chapter 3 Flashcards
1
Q
What is a cell?
A
the basic unit of structure and function in organisms
2
Q
Who discovered cells and when
A
Robert Hooke; 1665
3
Q
What is cell theory?
A
- All organisms are made up of one or more cells
- Cells are the basic unit of structure and function of all organisms
- All cells come from other cells that already exist
4
Q
Who invented the complex microscope
A
Antony van Leeuwenhoek
5
Q
What are the two types of cells
A
prokaryotic and eukaryotic
6
Q
what are prokaryotic cells
A
cells without a nucleus or membrane-bound organelles
7
Q
What are eukaryotic cells
A
cells with a nucleus and membrane-bound organelles
8
Q
Are all cells the same shape and size?
A
no
9
Q
why do cells come in different shapes and sizes
A
different tissues contain cells with different sizes and shapes for functional purposes
10
Q
What is a ligand?
A
A molecule that specifically binds to a receptor protein on a cell’s plasma membrane
11
Q
what are examples of ligands
A
hormones, neurotransmitters, nutrients, enzymes, ions, antibodies
12
Q
What are the main structures of a cell
A
plasma membrane (cell membrane)
nucleus
cytoplasm/organelles
13
Q
What is the function of the plasma membrane
A
- protection (serves as a barrier from the outside of the cell)
- semi-permeable/selectively permeable (allows only certain molecules to enter or exit)
- communication (allows cells to talk to their surroundings)
14
Q
What is the composition of the plasma membrane?
A
- lipids (phospholipids)(cell membrane)
- proteins (cell membrane)
- Carbohydrate chains
- some cholesterol
15
Q
What do the phospholipid molecules in the plasma membrane do?
A
- double layer that acts as a barrier for the cell
- allows oxygen, carbon dioxide, steriods to enter and exit but few other molecules can get through this layer
16
Q
What are the 3 cell surface proteins
A
marker proteins, channel proteins, and receptor proteins
17
Q
What do marker proteins do?
A
identify the cell
18
Q
What do channel proteins do?
A
allows specific molecules to enter and exit
19
Q
What do receptor proteins do?
A
allows cells to communicate
20
Q
What is the name given to cell surface proteins that extend through the lipid bilayer and may protrude from one or both sides of the cell membrane
A
integral protein
21
Q
What is cytoplasm
A
the area inside the cell surrounding the nucleus
22
Q
What is found inside the cytoplasm of the cell?
A
organelles
23
Q
What fluid is found in the cytoplasm of the cell?
A
cytosol
24
Q
How is the nuclear membrane similar to the cell membrane
A
they look the same and have the same composition
25
What does the nucleus contain?
DNA
Nucleolus (produces ribosomes)
26
The nucleus is enclosed by _____
the nuclear membrane
27
What does the nuclear membrane do
acts just like the plasma membrane of the cell
28
What is the composition of the nuclear membrane
- lipids (phospholipids)
- proteins
- Carbohydrate chains
- some cholesterol
29
What are the two ways in which molecules can enter and exit through the plasma membrane?
active transport and passive transport
30
What is passive transport
- no energy is used by the cell
- used to get things in and out of the membrane
- diffusion, osmosis, facilitated diffusion, filtration
31
WHat is active transport?
- cell's energy must be used (40%)
- endocytosis and exocytosis
32
What are the four types of passive transport systems?
diffusion, osmosis, facilitated diffusion, filtration
33
Which passive transport systems require a concentration gradient of high to low?
diffusion, osmosis, facilitated diffusion
34
How did molecules enter and exit through the plasma membrane?
passive and active transport
35
What is it called when molecules move from an area of high concentration to one of a low concentration through a cell's membrane
diffusion
36
What is it called when molecules
of water move from an area of high concentration to one of a low concentration through a cell's membrane
osmosis
37
What specific molecules in the human body enter and exit through diffusion?
oxygen, carbon dioxide, and steroids
38
How does osmosis differ from diffusion
- water instead of other molecules
- water moves through the pores in the membrane not directly through the phospholipid bilayer
39
When molecules are too large to enter or exit by normal means and instead have to enter or exit through special carrier proteins
facilitated diffision
40
Facilitated diffusion is how ___ and ___ enter the cell
glucose and some ions
41
Molecules are forced from regions of higher pressure to regions of lower pressure
filtration
42
Does filtration have to be from high concentration to low concentration?
no
43
What is an example of filtration
water leaving capillaries
44
What are the two types of active transport systems?
endocytosis and exocytosis
45
The movement of molecules in through the plasma membrane, usually too large to enter any other way
Endocytosis
46
What are the types of endocytosis
Pinocytosis
Phagocytosis
Receptor-mediated endocytosis
47
What is pinocytosis
fluids entering in through the plasma membrane
48
What is phagocytosis
solids (molecules like proteins and carbohydrates) entering in through the plasma membrane
49
The movement of moolecules out of the plasma membrane, that are usually too large to exit by itself
exocytosis
50
What is the definition of the cell cycle?
The life span/cycle of a cell. (The stages of a cell's life.)
The series of changes that a cell undergoes, from the time it forms until it divides.
51
What organelle forms ribosomes?
nucleolus
52
What organelle houses the genetic information (DNA)
nucleus
53
What organelle surrounds the nucleus?
nuclear membrane/envelope
54
What organelle provides structural support and enzymatic activity to link amino acids to synthesize proteins
ribosomes
55
What organelle forms the cytoskeleton
microtubules and microfilaments
56
What organelle is part of the centrosomes, cilia and flagella?
microtubules and microfilaments
57
What organelle forms bundles and provides cell motility?
microfilament
58
which is bigger: microfilament or microtubules
microtubules
59
What organelle moves fluids such as mucus over the surface of certain tissies
cillia
60
What organelle contains centrioles and microtubules?
centrosome
61
What organelle is the genetic information?
chromatin
62
What organelle refines, packages, and transports proteins synthesized on ribosomes associated with the ER
golgi apparatus
63
What organelle is primarily in the cytoplasm of liver and kidney cells
proxisomes
64
What organelle moves in a wave, which begins at its base, that allows the cell to "swim"
flagella
65
What organelle stores or transports distances within a cell between cells
vesicles
66
What organelle extracts energy from the nutrients in digested food? Where is it located?
mitochondria; cytoplasm
67
What organelle digests waste materials and cellular debrais using enzymes? It also recycles damaged organelles and helps defend against pathogens. Where is it located?
lysosomes; cytoplasm near the ER and golgi apparatus
68
What organelle stores excess water and food?
vacuoles (plants only)
69
What organelle can identify and dismantle misfolded proteins?
Endoplasmic reticulum
70
What organelle is a thread-like strand?
microtubules, and microfilaments
71
What organelle provides structural support and enzymatic activity to link amino acids to synthesize proteins?
ribosomes
72
What organelle has nuclear pores that allow certain molecules to exit the nucleus?
nuclear membrane/envelope
73
What organelle maintains the acidic pH that enables the enzymes to function and shield the rest of the cell from the acidic conditions?
lysosomes
74
What organelle transports molecules from one cell part to another
Endoplasmic reticulum
75
What organelle houses enzymes and catalyzes a variety of biochemical reactions
peroxisomes
76
What organelle (sometimes) has receptors that detect molecules that signal sensations to cells
(these organelles on cells deep in the nasal cavity assist in the sense of smell)
cillia
77
What 5 characteristics do cancers share and their meaning
hyperplasia - uncontrolled cell division
dedifferentiation - loss of specialized structures and functions of cell
invasiveness - ability of cancer cells to break through boundaries (basement membranes)
angiogenesis - induce extension of nearby blood vessels
metastasis - spread of cancer cells to other tissues through the bloodstream
78
what does the restriction checkpoint do
determines cells fate
whether it will continue to divide, become specialized, or die
79
what may cause cell division
stimulation from a hormone or growth factor
80
do all cells divide?
no; nerve cells do not divide
81
what cells need telomerase in order to stay long
bone marrow
82
when do chromosomes become visible
prophase
83
What is mitosis
division of the nucleus
84
What happens at prophase?
chromosomes become visible
centrioles move to opposite poles
nuclear membrane and nucleolus disappear
spindle fibers spread out
85
What happens at metaphase?
chromosomes line up in the middle of the nucleus and attach to a spindle fiber
86
What happens at anaphase
centromeres are pulled apart and chromatids become individual chromosomes
87
What happens at telophase
nuclear envelope forms as well as nucleolus
chromatid becomes chromatin
88
what is the definition of meiosis
process that separates the chromosomes in the nucleus of a germ cell, resulting in the production of four genetically different haploid nuclei
89
