LEC BSES 22 Flashcards
(126 cards)
1
Q
anything that occupies a space and has
mass
A
matter
2
Q
smallest particle of an element.
A
atom
3
Q
two or more atoms joined
A
molecule
4
Q
composed of atoms from more than one elements
A
compound
5
Q
formed when 2 atoms share a pair of electrons
A
covalent bond
6
Q
do not depend on shared electrons but rather on attractive forces between atoms having an opposite charge
A
noncovalent bonds
7
Q
formed when electrons are donated by one atom to another
A
ionic bond
8
Q
is the attractive force between the hydrogen attached to an electronegative atom of one molecule and an electronegative atom of a different molecule
A
hydrogen bond
9
Q
occurs between the two strands of a DNA molecule
A
hydrogen bond
10
Q
this enables dissolve many substances, and thus it is called the universal solvent
A
high polarity
11
Q
water does not increase in temperature easily
A
high specific heat capacity
12
Q
1 calorie is required to increase the temperature of 1 gram of water by 1 degree celsius
A
high specific heat capacity
13
Q
a large amount of heat energy has to be removed from water to freeze it
A
high heat of fusion
14
Q
to turn 1 gram of liquid water into water vapor, much heat is needed (more than 500 calories)
A
high heat of vaporization
15
Q
prevents organisms from losing all of the water in their body during a warm day
A
high heat of vaporization
16
Q
allows the movement of blood cells through tiny capillaries
A
high surface tension but low viscosity
17
Q
capillary action cause the upward movement of water
A
strong cohesive forces between water molecules
18
Q
physiological properties of water
A
-moistens surfaces for gas diffusion
-regulates body temperature
-transporting medium
19
Q
biomolecules
A
-carbohydrates
-lipids
-proteins
-nucleic acids
20
Q
functions of carbohydrates
A
-* provides energy
* short-term energy storage
* form part of the structural framework of
DNA and RNA molecules
* Carbohydrates linked to lipids are
structural components of cell membranes
* Carbohydrates linked to proteins function
in cell-to-cell recognition
21
Q
Monosaccharides (C6H12O6)
A
glucose, fructose, galactose
22
Q
Disaccharides (C12H22O11)
A
sucrose = glucose + fructose
lactose = glucose + galactose
maltose = glucose + glucose
23
Q
Polysaccharides
A
-starch, glycogen, cellulose
24
Q
simple sugars are linked in long chains
(glycosidic bonds)
A
Polysaccharides
25
functions of Polysaccharides
1. for storage
2. serve as building material for
structures that protect cells & support
whole organisms
26
the splitting of molecule by adding water
-opposite of dehydration synthesis
*Hydrolysis
27
is converted into soluble
monosaccharide before it can be used by
animals
starch
28
identical to starch except that it is more
extensively branched
Glycogen
29
serves as a storehouse of
surplus chemical energy in most animals
Glycogen
30
can’t be hydrolyzed by most animals
Cellulose
31
have cellulose-hydrolyzing
microorganisms in their digestive tracts
cows and termites
32
Linked by nonpolar covalent bonds
lipids
33
functions of lipids
-cell membrane structure
- source of energy
-energy storage
-hormone synthesis
34
”triglyceride” or “triacylglyceride”
fats
35
made of glycerol and 3 fatty acids
fats
36
structurally similar to fats, but it contains P and 2
fatty acids instead of 3
Phospholipid
37
more hydrophobic than fats
waxes
38
-ex: cholesterol
steroid
39
-have an amino group and a
carboxyl group
proteins
40
linked by peptide bonds
proteins
41
building blocks of proteins
amino acids
42
selective acceleration of chemical reactions
enzymatic proteins
43
protection against defensive
defensive proteins
44
storage of amino acids
storage proteins
45
transport of substances
transport proteins
46
is sequence of amino acids
primary protein structure
47
local conformation primarily stabilized by hydrogen bonding
secondary protein structure
48
three dimensional conformation
tertiary protein structure
49
combination of multiple polypeptide chains
quaternary protein structure
50
building blocks of nucleic acids
nucleotides
51
nucleotides are joined together by
phosphodiester bonds
52
functions of nucleic acids
* information storage
* protein synthesis
* carry chemical energy
* used as small intracellular
signaling molecules
53
characteristics of DNA
double helix structure
anti-parallel: each strand
runs in opposite direction
has complementary base
pairing (Chargaff's rule)
composed of nucleotides
can mutate
can be denatured by heat
54
location of DNA
nucleus, mitochondria, chloroplasts
55
location of RNA
nucleus and cytoplasm
56
semipermeable / selectively permeable
plasma membrane
57
refers to the process by which cells form contacts with each other (cell-cell adhesions) or with their substratum in their surroundings as well as the extracellular matrix (cell-ECM adhesions)
cell adhesion
58
essential for the formation and maintenance of multicellular tissues, particularly epithelia
cell-cell adhesion
59
is the detection of specific signals at the cell surface by regulatory mechanisms where these signals are transmitted into the cell leading to the expression of certain genes and or changes in cell behavior
signal transduction
60
allows specialized activities to proceed without external interference and enables cellular activities to be regulated independently of one another
compartmentalization
61
membranes prevent the unrestricted exchange of molecules from one side to the other
providing a selectively permeable barrier
62
membranes are intimately involved in the processes by which one type of energy is converted to another type
energy transduction
63
functions of cell membrane
-cell adhesion
-signal transduction
-vacuole formation
-compartmentalization
-providing a selectively permeable barrier
-transporting solutes
-energy transduction
64
addition of saccharides to proteins or lipids to form glycoprotein or glycolipid
glycosylation
65
function of membrane carbohydrates
-as components of recognition sites of membrane receptors
-protect the protein from digestion by extracellular proteases
-membrane stablity
66
has small polar head attached to a lipid membrane
phospholipids
67
carbohydrate groups added to lipids
glycolipids
68
reduces bilayer permeability (filling in spaces between hydrocarbon chains)
cholesterol
69
membrane proteins
1. peripheral proteins
2. integral proteins
a. marker proteins
b. transport proteins
70
functions of membrane proteins
-as enzymes
-transport
-receptor-recognition and mediation of specific chemical signals (hormones, neurotransmitters, growth-promoting substances)
-communication
-structural roles - stabilizing and shaping the cell membrane
71
allows a particular molecule or ion to cross the plasma membrane freely. cystic fibrosis, an inherited disorder, is caused by a faulty chloride channel; a thick mucus collects in pancreatic and liver ducts
channel protein
72
selectively interacts with a specific molecule or ion so that it can cross the plasma membrane. the inability of some persons to use energy for sodium-potassium transport has been suggested as the cause of their obesity
carrier protein
73
the MHC (major histocompatibility complex) glycoproteins are different for each person, so organ transplant are difficult to achieve. cells with foreign MHC glycoproteins are attacked by white blood cells responsible for immunity
cell recognition protein
74
is shaped in such a way that a specific molecule can bind to it. pygmies are short, not because they do not produce enough growth hormone, but because their plasma membrane growth hormone receptors are faulty and cannot interact with growth hormone
receptor protein
75
catalyzes a specific reaction. the membrane protein, adenylate cyclase, is involved in ATP metabolism. cholera bacteria release a toxin that interferes with the proper functioning of adenylate cyclase; sodium ions and water leave intestinal cells, and the individual may die from severe diarrhea
enzymatic protein
76
between the cell and its environment
cellular transport
77
across membranes of organelles within the cell
intracellular transport
78
occurs through cell layers
transcellular transport
79
down the concetration gradient
passive transports
80
toward lower concentration
simple diffusion
81
movement of water through a semipermeable membrane from a region of lower solute concentration to a region of higher solute concentration
osmosis
82
similar in many ways to an enzyme-catalyzed reaction. like enzymes, facilitative transporters are specific for the molecules they transport
facilitated diffusion
83
macromolecules transported into or out of the cell inside vesicles
bulk transports
84
vesicles fuse with plasma membrane and secrete contents
exocytosis
85
cells engulf substances into pouch which becomes a visicle
endocytosis
86
functions of basement membrane or basal lamina
-provide mechanical support for the attached cells
-generate signals that maintain cell survivor
-serve as substratum for cell migration
-separate adjacent tissues within an organ
-act as a barrier to the passage of macromolecules
87
comprise of fibrous glycoproteins
collagen
88
high tensile strength
collagen
89
produced primarily by fibroblasts, the cells found in various types of connective tissues, but also by smooth muscle cells and epithelial cells
collagen
90
for mechanical support
collagen
91
consists of a core protein molecule to which chains of glycosaminoglycans are covalently attached
proteoglycans
92
resists crushing forces
proteoglycans
93
give cartilage and other EMC strength and resistance to deformation
collagen and proteoglycans
94
binding sites for numerous components of the ECM
fibronectin
95
binding sites for receptors on the cell surface
fibronectin
96
play a critical role in the migration of primordial germ cells
laminin
97
both strength and flexibility for ECM
laminin
98
most important family of receptors that attach cells to their extracellular microenviroment
integrins
99
found only in animals that play a key role in integrating the extracellular and intracellular enviroments
integrins
100
comprise a family of integral membrane glycoproteins that recognize and bind to a particular arrangement of sugars
selectins
101
it is mediate transient interactions between circulating leukocytes and vessel walls at sites of inflammation and clotting
selectins
102
involved in various aspects of immune function, but some of these proteins mediate calcium-independent cell-cell adhesion
immunoglobulin superfamily or IgSF
103
join cells of similar type to one another by binding to the same cadherin present on the surface of the neighboring cell
cadherins
104
common in epithelia, such as the lining of the intestine
adherens junctions
105
numerous in tissues that are subjected to mechanical stress, such as cardiac muscle and the epithelial layers of the skin and uterine cervix
desmosomes
106
these junctions are evident in the brain where they help form the blood-brain barrier which prevents substances from passing from the bloodstream into the brain
tight junctions
107
sites between animal cells that are specialized for intercellular communication
gap junctions
108
composed entirely of an integral membrane protein called
connexin
109
connexins are organized into multisubunit complexes, called
connexons
110
cytoplasmic channels that pass through the cell walls of adjacent cells
plasmoodesmata
111
serve as sites of cell-to-cell communication
plasmodesmata
112
the shape of the nucleus is maintained by a net of filaments called the
nuclear lamina
113
when the cell is not dividing, a nucleus contains a
nucleolus
114
the nucleolus is a dense region ___ where is made
rRNA
115
in the nucleolus, rRNA combines with proteins to form
ribosomes
116
the DNA is organized and packaged into
chromosomes
117
cell increases in volume/double its mass
organelles are formed (mitochondria, chloroplasts,
Golgi apparatus)
g1
118
active synthesis of DNA and histones
(components of chromatin)
s phase
119
-active synthesis of RNA and proteins for
chromosome synthesis, mitotic spindles are
formed
g2
120
creates two new cells
with identical genetic
information (diploid)
mitosis
121
keeps the chromosome number constant (generation
after generation)
meiosis
122
produces gametes or spores that are characterized by
only one haploid set of chromosomes.
meiosis
123
proposed the chargaff's rule
erwin chargaff
124
after the DNA is transcribed into RNA, editing must be done to the nucleotide chain to make the RNA functional
mRNA processing
125
intron splicing
spliceosome
126
a mature mRNA strand will leave through nuclear pores and enter cytoplasm to begin translation
spliceosome
