biology EXAM #2 pt.2 Flashcards

1
Q

Macromolecules and Polymers :

-Are…
examples:

-Are…
For example:

A
  • large molecules composed of smaller molecules
    Carbohydrates, lipids, proteins, nucleic acids

-complex in their structures
one hemoglobin molecule = thousands of covalently connected atoms, two polypeptide chains making one protein (quaternary structure)

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2
Q

Most macromolecules are ________, built from _____

A

-polymers

-monomers

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3
Q

Polymer =

A

a long molecule consisting of many similar building blocks called monomers

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4
Q

Three of the classes of life’s organic
 molecules are

A

polymers formed from a specific set of monomers

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5
Q

examples

polymers

monomers

A

-carbohydrates, protein, nucleic acid

-monosaccharide, amino acid, nucleotide

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6
Q

Although organisms share:
, each organism is :

An immense variety of polymers can be built from a:

A

-the same limited number of monomer types

-unique based on the arrangement of monomers into polymers

-small set of monomers

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7
Q

four important classes of biological molecules

three are:

one is:

A

-macromolecules: -carbohydrates, proteins, nucleic acids,

-not polymer or macromolecules: lipids

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8
Q

what are they made of:

-carbohydrates (starch):

-protein:

-nucleic acids:

A
  • glucose

-amino acids

-nucleotide

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9
Q

These processes are facilitated by ________, which are:

A

enzymes

-specialized protein molecules that speed up the chemical reactions

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10
Q

Monomers
form what with what bond and how?

A

-by means of covalent bonds, form larger molecules or polymers by condensation reactions or dehydration reactions

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11
Q

Polymers can disassemble by ________ - ____ _____ = for example in digestion, it is assisted by ____ (i.e. lactose dehydrogenase, pancreatic lipases)

A

-Hydrolysis- needs water

-enzymes

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12
Q

A cell has thousands of :
Macromolecules vary among cells of an organism, vary more within a species, and vary even more between species
A huge variety of polymers can be built from

A

-different macromolecules

-a small set of monomers

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13
Q

Carbohydrates serve as

Carbohydrates include both :

A

-fuel and building material, structure, cell to cell recognition

-simple monosaccharides or simple sugars and their macromolecules or polysaccharides (polymers)

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14
Q

Monosaccharides:
-what is it?
-what functional group

A
  • simplest sugars usually multiples of CH2O.

-Carbonyl as the functional group >C=O, and multiple hydroxyl groups –OH

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15
Q

Sugars can be divided into:
and this depends on:

A

-May be of two classes:
aldoses (aldehyde sugars) tiene el c=o diagonal
ketoses (ketone sugars,), tiene el c=o recto paralelo

-depending on the location of the carbonyl group

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16
Q

Sugars are also classified according to the:

A

length of their carbon skeletons:
hexoses, pentoses, trios.

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17
Q

sugars

first point of variation

second point

A third point of variation is the:

A

-position of the carbonyl group

-length of their carbon skeleton

  • spatial arrangement around asymmetric carbons
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18
Q

Monomers:
can be used as…
can be converted..
can be combined…

A

Can be used for fuel
Can be converted into other organic molecules
Can be combined into polymers

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19
Q

Monosaccharides
Though often drawn as linear skeletons, in aqueous solutions…

A

many sugars form rings

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20
Q

Disaccharides:

A

double sugars - covalent bond called glycosidic linkage

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21
Q

dehydration (condensation) reaction:

A

1,4 linkages through dehydration reaction

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22
Q

3 common disaccharides

A

a. maltose = glucose + glucose = brewing beer
b. lactose = glucose + galactores = milk
c. sucrose = glucose + fructose = table sugar

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23
Q

Dehydration reaction 
in the synthesis of 
maltose. The bonding 
of ___ ___ ____ 
forms maltose. The 
glycosidic link joins _______________________________. 
Joining the glucose 
monomers in a 
different way would 
result in a different 
disaccharide.

A

-two glucose units

-
the number 1 carbon 
of one glucose to the 
number 4 carbon of 
the second glucose

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24
Q

Dehydration reaction 
in the synthesis of 
sucrose. Sucrose is _________________________.
Notice that fructose,
though a hexose like 
glucose, forms a 
five-sided ring.

A

-
a disaccharide formed 
from glucose and fructose

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25
Q

The architecture and function of a polysaccharide are determined by

A

its sugar monomers and the positions of its glycosidic linkages

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26
Q

polysaccharides serve many roles in organisms

A
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27
Q

two types of polysaccharides

A

storage polysaccharides– providing sugar to cells – storage in plastids including chloroplasts

Structural polysaccharides : Building material for structures

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28
Q

storage polysaccharides–
two examples

A
  1. starch in plants (glucose monomers)
    a)-alpha (starch) versus beta (cellulose) glucose
    b)-amylose – simple form of starch: unbranched
    c)-amylopectin – more complex form of starch – branched polymer with 1-6 linkages at branch points
    1. glycogen– in animals (glucose monomers) more branches –storage in liver and muscle cells
29
Q

Starch

it is the major…

plants store…

simplest form is…

A

It is the major storage form of glucose in plants.

Plants store surplus starch 
as granules within 
chloroplasts and other 
plastids

The simplest form of 
starch is amylose

30
Q

glycogen

consists of…

it is the major…

stored mainly in…

what to do when the demand for sugar increases…

A

Consists of glucose monomers

Is the major storage form of glucose in animals

Glycogen is stored mainly in liver and muscle cells

Hydrolysis of glycogen in these cells releases glucose when the demand for sugar increases

31
Q

Structural polysaccharides :

info-

two examples:

has…

major component of…

A

-Building material for structures

– straight never branched polysaccharide hydrogen bonding between the hydroxyl groups of C 3 and C 6 of other molecules lying paralleled to it

i. Cellulose- in plants
ii. Chitin – in arthropods and some fungi. – N- containing appendage. It is a polymer of glucose

Has different glycosidic linkages than starch

Is a major component of the tough walls that enclose plant cells

32
Q

enzymes that digest starch by hydrolyzing a linkages can’t…

the cellulose in human food passes…

some microbes use…

many herbivores have…

A

Enzymes that digest starch by hydrolyzing α linkages can’t hydrolyze β linkages in cellulose

The cellulose in human food passes through the digestive tract as “insoluble fiber”

Some microbes use enzymes to digest cellulose

Many herbivores, from cows to termites, have symbiotic relationships with these microbes

33
Q

starch is largely…

cellulose molecules are…

some hydroxyl groups can…

A

helical

are straight and unbranched

Some hydroxyl groups on the monomers of cellulose can hydrogen-bond with hydroxyls of parallel cellulose molecules

34
Q

Cellulose is difficult to digest cows have…

A

microbes in their stomachs to facilitate this process

35
Q

Another important structural polysaccharide is…

Is found in…

Can be used as…

it has a…

it forms the…

A

Chitin

the exoskeleton of arthropods (embedded in a layer of proteins)and many fungi (instead of cellulose for the cell wall)

surgical thread

nitrogen containing attachment

exoskeleton of arrthropods

36
Q

main diff between starch and cellulose

A

*starches – more helical


*cellulose molecule- straight and never branched and the -OH group can h-bond with other –OH from other cellulose

37
Q

Lipids are…

function:

are the one class that…

structure:

A

Are a diverse group of hydrophobic molecules (ie: fats, phospholipids and steroids)

Function – many , they vary: energy storage more than starch, cushions vital organs (kidney), insulation

Are the one class of large biological molecules that do not consist of polymers

Structure – two small molecules:

·glycerol – an alcohol with 3 C, each with a hydroxyl group (-OH)

·fatty acid -16-18 C chain with a carboxyl group ( OH-C=O) and a non polar C-H bond at the other end.

·Dehydration reaction forming an esther linkage. Share the common trait of being hydrophobic

38
Q

Fat molecule or triacylglycerol

structure:

A

Structure: a single glycerol and usually three fatty acids bonded by esther linkages

39
Q

Fatty acids

vary in the…

types of fat:

A

-Vary in the length and number and locations of double bonds they contain

Types of fat:
a.saturated (single bonded C atoms), the molecule can pack tightly side by side – most animal fat,

b. unsaturated (double bonded C atoms), plants and fishes, the cis double bonds prevent it from solidifying at room T.

40
Q

Saturated fatty acids
Have the maximum number of…

Have no…

At room temperature…

A

Have the maximum number of hydrogen atoms possible

Have no double bonds

At room temperature, they are solid

41
Q

Unsaturated fatty acids

Have one or more…
At room temperature they…

A

Have one or more double bonds

At room temperature they cannot solidify, so they are liquid

42
Q

Fats made from saturated fatty acids are called…

Most animal fats are…

Fats made from unsaturated fatty acids are
 called…

Plant fats and fish fats are…

A

are called saturated fats and are solid at room temperature

saturated

are 
called unsaturated fats or oils and are liquid at room temperature

unsaturated

43
Q

A diet rich in saturated fats may contribute to…

Hydrogenation is the process of…

Hydrogenating vegetable oils also creates…

These trans fats may contribute…

A

contribute to cardiovascular disease through plaque deposits

converting unsaturated fats to saturated fats by adding hydrogen

creates unsaturated fats with trans double bonds

contribute more than saturated fats to cardiovascular disease

44
Q

Certain unsaturated fatty acids are not…

These must be…

These essential fatty acids include the….

The major function of fats is…

Humans and other mammals store their long-term food reserves in…

Adipose tissue also…

A

are not synthesized in the human body

supplied in the diet

include the omega-3 fatty acids, which are required for normal growth and are thought to provide protection against cardiovascular disease

is energy storage

in adipose cells

also cushions vital organs and insulates the body

45
Q

phospholipids

have only…

have a…

When phospholipids are added to water…

At the surface of a cell, phospholipids are also arranged in a….

The phospholipid bilayer forms a…

A

Have only two fatty acids (the hydrophobic “tails”)

Have a phosphate group instead of a third 
fatty acid (the hyrophilic “head”)

When phospholipids are added to water, they
 self-assemble into double-layered sheets 
called bilayers

At the surface of a cell, phospholipids are also arranged in a bilayer, with the hydrophobic tails pointing toward the interior

The phospholipid bilayer forms a boundary between the cell and its external environment

46
Q

steroids

Are…

Types of steroids vary in ____________. Cholesterol is…

Also found in…

A high level of cholesterol in the blood may contribute to-…

A

Are carbon skeleton of 4 fused rings

in functional group. Cholesterol is precursor of other steroid synthesis such as vertebrate sex hormones (testosterones, estradiol)

in 
cell membranes

contribute to cardiovascular disease.

47
Q

emulsificaions

Fats are ________; they do not ______________________ and tend to form “__________” (think of oil and vinegar salad dressing)

Emulsifier breaks down…

Emulsifiers have a…

A

Fats are nonpolar; they do not dissolve in water and tend to form “globules” (think of oil and vinegar salad dressing)

Emulsifier breaks down the globules of fat into smaller droplets

Emulsifiers have a nonpolar end which attaches to the fat, and a polar end which interacts with water molecules so that the droplets can disperse

48
Q

Proteins have…

account for…

Function: many –

A

Proteins have many structures, resulting in a wide range of functions.

-account for more than 50% of the dry mass of most cells

Function: many –
a.speed up chemical reactions,
b. structural support,
c.storage,
d. transport,
e. cellular communications,
f.movement,
g.defense against foreign substances.

49
Q

8 types of proteins: name, function,example

A

enzymatic proteins: Selective acceleration of
chemical reactions. Example: digestive enzymes

defensive proteins: Protection against disease. Example: antibodies

storage proteins: Storage of amino acids. Example: CASEIN, the protein of milk, is the major source of amino acids for baby mammals. Plants have storage proteins in their seeds. OVALBUMIN is the protein of egg white, used as an amino acid source for the
developing embryo.

transport proteins: Transport of substances. Example: Hemoglobin, the iron-containing protein of vertebrate blood, transports oxygen from the lungs to other parts of the body.

Hormonal proteins: Coordination of an organism’s
activities. Example: Insulin, a hormone secreted by the pancreas, causes other tissues to take up glucose, thus regulating blood sugar, concentration.

Receptor proteins: Response of cell to chemical stimuli. Example: Receptors built into the membrane of a nerve cell detect signaling molecules released by other
nerve cells.

Contractile and motor proteins: Movement. Example: Motor proteins are responsible for the undulations of cilia and flagella. Actin and myosin proteins are responsible for the contraction of muscles.

Structural proteins: Support. Example: Keratin is the protein of hair, horns, feathers, and other skin appendages. Insects and spiders use silk fibers to make their cocoons and webs, respectively. Collagen and elastin proteins provide a fibrous framework in animal
connective tissues.

50
Q

Enzymes , perhaps most important..

Are a type of protein that…

A

Enzymes , perhaps most important proteins

Are a type of protein that acts as a catalyst, speeding up chemical reactions

51
Q

Polypeptides are…

all proteins made up of-….

A

Are polymers of amino acids bonded by of peptide bonds

all proteins made up of one or more polypeptides of same 20 a.a. folded and coiled in a specific conformation.

52
Q

Amino acids are…

Differ in their…

The R groups or side chains
 determine the…

___ different amino acids make up proteins

A

Are organic molecules possessing both carboxyl and amino groups

Differ in their properties due to differing side chains, called R groups

The R groups or side chains
 determine the characteristics 
of a particular a.a.

20 different amino acids make up proteins

53
Q

amino acids

Types of side chains: (3)

Are linked by…

The sequence of amino acids determines…

A protein’s structure determines…

The function of a protein usually depends on
…

A

a.polar – hydrophilic

b. Electrically charged:
i.acidic – negatively charged due to carboxyl group on side chain – dissociated at cell Ph
ii.basic – positively charged due to amine groups on side chain

c. nonpolar – hydrophobic

linked by peptide bonds

determines a protein’s three-dimensional structure

determines how it works

depends on 
its ability to recognize and bind to some other molecule

54
Q

one protein = _____________________. Some are _____, other ____

The ___________________ determines its function.

The function depends on:
a.
b.

A

one protein = one or more polypeptides precisely twisted, folded and coiled into a molecular unique shape. Some are globular, other fibrous.

The conformation of a protein determines its function.

The function depends on
a.its ability to recognize and bind to a molecule, related to shape.
i.e: endorphins. ➔ Natural drug, morphine, heroin, and other opiate mimic endorphins because share similar shape thus fitting and binding in receptors in the brain.

55
Q

Determining the Amino Acid Sequence of a Polypeptide

The amino acid sequences of polypeptides:

Were first determined…
Can now be determined…

A

Were first determined using chemical means

Can now be determined by automated machines

56
Q

Four levels of protein structure

A

Primary structure: is the unique sequence of amino acids in a polypeptide.

Secondary structure: is the folding or coiling of the polypeptide into a repeating configuration. Includes the α helix and the β pleated sheet and random coils

Tertiary structure: is the overall three-dimensional shape of a polypeptide. Results from interactions between amino acids and R groups

Quaternary structure: is the overall protein structure that results from the aggregation of two or more polypeptide subunits (collagen, hemoglobin)

57
Q

Sickle-cell disease
Results from…

capacity…

A

Results from a single amino acid substitution in the protein hemoglobin

capacity to carry oxygen is reduced

58
Q

protein conformation

Depends on the…

In addition to primary structure,

Alterations in…

This loss of a protein’s native structure is
 called…, which is…

A __________ protein is…

A

Depends on the physical and chemical conditions of the protein’s environment

physical and chemical conditions can affect structure

Alterations in pH, salt concentration,
temperature, or other environmental factors
 can cause a protein to unravel

is
 called denaturation, which is when a protein unravels and loses its native conformation

A denatured protein is biologically inactive

59
Q

The cellular environment may affect…

It may….
a)
b)
c)

Some denaturing agents:

Turn ________________, or may disrupt…

Example:

A

affect protein conformation.

It may denature it which inactivates it…

a) heat
b) pH
c) salt concentration

Some denaturing agents:
Turn hydrophilic ends outward, or may disrupt H-bonds, ionic bonds, disulfide bridges thus changing shape of protein
Example: Organic solvents (ether, chloroform)

60
Q

Most proteins probably go through…

Chaperonins are…

Steps of Chaperonin
 Action:

1.
2.
3.

A

several intermediate states on their way to a stable conformation

Are protein molecules that assist in the proper folding of other proteins

  1. An unfolded poly-
peptide enters the 
cylinder from one end.
  2. The cap attaches, causing the cylinder to change shape in
such a way that it creates a hydrophilic environment for the folding of the polypeptide.
  3. the cap comes
off, and the properly
folded protein is released.
61
Q

Nucleic acids store and transmit…

Genes_
-Are
-Program
-Are made of

There are two types of nucleic acids:

Nucleic acids exist as…

Each polynucleotide consists of…

A

Nucleic acids store and transmit hereditary information

Genes:
-Are the units of inheritance
-Program the amino acid sequence of polypeptides
-Are made of nucleic acids

Deoxyribonucleic acid (DNA)
Ribonucleic acid (RNA)

Nucleic acids exist as polymers called polynucleotides

consists of monomers called nucleotides

62
Q

DNA
stores:
directs:
directs:

A

Stores information for the synthesis of specific proteins
Directs RNA synthesis
Directs protein 
synthesis through 
RNA

63
Q

Nucleotide monomers - Are made up of…

Nucleoside =

There are two families of nitrogenous bases:

In DNA, the sugar is ________; in RNA, the sugar is ________

A

Are made up of nucleosides and phosphate groups

Nucleoside = nitrogenous base + sugar

-Pyrimidines (cytosine, thymine, and uracil)
have a single six-membered ring
-Purines (adenine and guanine) have a six-membered ring fused to a five-membered ring

In DNA, the sugar is deoxyribose; in RNA, the sugar is ribose

64
Q

Nucleotide polymers are made up of…

The joining between nucleotides is called… , which consists of…

The sequence of bases along a nucleotide polymer is…

Cellular DNA molecules have …

The nitrogenous bases in DNA form …

A

Are made up of nucleotides linked by the–OH group on the 3´ carbon of one nucleotide and the phosphate on the 5´ carbon on the next

is called phosphodiester linkage, which consists of a phosphate group that links the sugars of two nucleotides.

is unique for each gene

have two polynucleotides that spiral around an imaginary axis forming a double helix

form hydrogen bonds in a complementary fashion (A with T only, and C with G only)

65
Q

The DNA double helix consists of…

RNA, in contrast to DNA, is…

Complementary pairing can also occur between…

In RNA, ______ is replaced by ______ so…

While DNA always exists as a double helix,
RNA molecules are…

A

Consists of two antiparallel nucleotide strands

is single stranded.

between two RNA molecules or between parts of the 
same molecule

In RNA, thymine is replaced by uracil (U) so
 A and U pair

are more variable in form

66
Q

Molecular comparisons help biologists…

Remember, DNA is passed on from parent to offspring (with modifications) and closer related species share greater proportions of their DNA than do most distantly related species.

A

Help biologists sort out the evolutionary connections among species

67
Q

Analyzing large sets of genes or even comparing whole genomes of different species is called _______:

-Once the structure of DNA and its relationship to amino acid sequence was understood, biologists sought to…

-The first chemical techniques for DNA sequencing were developed in the…

A similar analysis of large sets of proteins including their sequences is called _______

A

genomics

Once the structure of DNA and its relationship to amino acid sequence was understood, biologists sought to “decode” genes by learning their base sequences

  • in the 1970s and refined over the next 20 years

-proteomics

68
Q

It is enlightening to sequence the full complement of DNA in an organism’s genome

The rapid development of faster and less expensive methods of sequencing was a side effect of the…

Many genomes have been sequenced, generating…

A

It is enlightening to sequence the full complement of DNA in an organism’s genome

-of the Human Genome Project

generating reams of data

69
Q

contributions of genomics and proteomics to biology

A

paleontology, evolution, medical science, conservation biology, species interactions.