Unit 1 Flashcards
(101 cards)
1
Q
what does CHARRGED stand for
A
Cell, Homeostasis, Adapts, Responds, Reproduces, Grows, Energy, DNA
2
Q
what are the 8 processes IB wants you to know
A
Metabolism, Response to Stimuli, Homeostasis, Movement, Growth, Reproduction, Excretion, Nutrition
3
Q
what is biology
A
bio- life // ology- the study of
4
Q
Charrged (cells)
A
living things are made up of one or more cells // organisms can be unicellular (made of one cell) or multicellular (made of more than one cell)
5
Q
chArrged (adapt/evolve)
A
over generations, groups of living things change over time (because their genetic information changes). this is known as adaptation and evolution
6
Q
cHarrged (homeostasis)
A
the ability to maintain a constant internal environment is called maintaining homeostasis
7
Q
chaRrged (response)
A
organisms notice and react to stimuli from their environment // reacting to stimuli (changes in the environment) can often lead to movement
8
Q
charRged (reproduce)
A
all living things make new, similar, living things
9
Q
charrGed (grow)
A
every organism has a pattern of growth and development
10
Q
charrgEd (energy)
A
all living things must take in materials & energy // many chemical reactions occur within living things in order to build up and break down materials to facilitate these processes. all of these chemical reactions together are known as “metabolism”
11
Q
charrgeD (DNA)
A
all living things store the information they need to live, grow, and reproduce in a genetic code written in a molecule called DNA
12
Q
3 things about cell theory
A
- all living things are made of one or more cells
- cells are the basic unit of life
- cells come from pre-existing cells
13
Q
3 things about the conditions on early earth
A
- early earths atmosphere lacked free oxygen & ozone and had an abundance of CO2 and CH4 (carbon dioxide & methane)
- without ozone, there was more UV light that reached the surface of the earth
- CO2 & CH4 are greenhouse gases - gases that trap heat - increasing the temperature of early earth
14
Q
miller and urey’s experiment
A
created an experiment to stimulate the conditions on prebiotic earth they investigated what types of molecules could form in the conditions of early earth (combined H2O, CH4, NH3, and H2 with heat and electricity: under these conditions, several simple organic molecules, including amino acids were found)
15
Q
formation of the first cells
A
- the first cells (proto cells) had to have formed spontaneously and in an aqueous environment
- self-replication of molecules and self-assembly of cells were necessary for the evolution of the first cells
- protocells must have been significantly less complex than current cells
16
Q
spontaneous formation of vesicles
A
- when in an aqueous environment, fatty acids will spontaneously self-assemble to form spherical bilayers
- the spherical bilayer forms a membrane that separates the internal environment from the external environment
17
Q
what does RNA stand for
A
ribonucleic acid
18
Q
what is RNA thought to be
A
RNA is thought to have been the first genetic material - not only can RNA act as genetic material, but it also has catalytic properties
19
Q
what does LUCA stand for
A
Last Universal Common Ancestor
20
Q
what is the evidence for LUCA
A
- universal genetic code
- conserved genes across all organisms
21
Q
what was LUCA likely to be
A
a unicellular, autotrophic, microbe that existed between 2.5 and 3.5 billion years ago
22
Q
LUCA and hydrothermal vents
A
- fossilized evidence suggests that LUCA could have evolved around the hydrothermal vents
- hydrothermal vents remain a hotbed of life even today
- organisms thrive in the mineral rich environment surrounding the vents
23
Q
COMPARISONS of prokaryotic and eukaryotic cell structure
A
- have DNA
- have a cell membrane
24
Q
CONTRASTS of prokaryotic and eukaryotic cell structure
A
- prokaryotic cells have flagellas whereas eukaryotic cells do not
- eukaryotic cells have a nucleus whereas prokaryotic cells have a nucleoid
25
what kind of cells have ribosomes
all of them
26
what is the difference between eukaryotic and prokaryotic ribosomes
prokaryotic cells: 70s // eukaryotic cells: 80s
27
eukaryotes include...
plants, animals, fungi, protists
28
inside of an animal cell
1. a place where the cells activities are controlled
2. a place where chemical reactions happen
3. a place where substances can pass in and out of the cell
4. a place where energy is release for the cell
29
inside of a plant cell
1. same features as animal cells
2. a place where light is captured for photosynthesis
3. a place where water & other materials are stored
4. a place to help support and strengthen the cell
30
both type of cells have these:
mitochondria, ribosomes, nucleus, cell membrane, cytoplasm
31
only plant cells have these
central vacuole, chloroplasts, cell wall
32
what is a flagella
lash-like appendage that protrudes from the cell body
33
what is a cilia
slender protuberances that project from the much larger cell body
34
atypical cell structure in eukaryotes
numbers of nuclei illustrate one type of atypical cell structure in aseptate fungal hyphae, skeletal muscle, red blood cells, and phloem sieve tube elements
35
aseptate fungal hyphae
- challenges the idea that a cell is a single unit
- fungal hyphae are very large, forming a tubular system with many nuclei and a continuous cytoplasm
- like muscle cells they are multi-nucleated
- they have cell walls composed of chitin
- the cytoplasm is continuous along the hyphae with no end cell wall or membrane
36
striated skeletal muscle
- challenges the idea that a cell has one nucleus
- muscle cells have more than one nucleus per cell
- muscle cells called fibres can be very long (300 mm)
- they are surrounded by a single plasma membrane but they are multi-nucleated (many nuclei)
- this does not conform to the standard view of a small single nuclei within a cell
37
red blood cells
- red blood cells have no nucleus when they are mature to allow for more hemoglobin storage
- red blood cells have no DNA and thus cannot replicate bone marrow must continually produce new RBC's
- the atypical structure of RBC's challenges the cell theory
38
phloem sieve tubes in plants
- sieve elements line the phloem in plants and are interconnected into tube assemblies that transverse the length of a plant
- these sieve tubes lack nuclei and have few organelles, relying on local companion cells for survival
- phloem sieve tubes challenge the idea that multicellular structures are composed of independent cells
39
endosymbiotic theory
- lynn margulis (1964)
- "eukaryotic cells evolved from prokaryotic cells"
- major organelles in eukaryotic cells are thought to have once been prokaryotic cells that established symbiotic relationships
- mitochondria & chloroplasts
40
evidence supporting endosymblosis
- mitochondria and chloroplasts have a double membrane
- mitochondria and chloroplasts have their own ribosomes
- mitochondria and chloroplasts have circular DNA
- mitochondria and chloroplasts reproduce independently of the rest of the cell and in a way that is similar to binary fission
41
why is it thought that what is now mitochondria, was engulfed first, then what is now chloroplasts was engulfed
if the chloroplast came first, then some cells would have had to lose their chloroplasts, then they all would have had to engulf the mitochondria
42
organic chemistry = carbon chemistry
- the study of compounds that contain carbon
- organic molecules range from simple to colossal
43
carbon - selection of life
- although cells are 70-95% water, the rest consists mostly of carbon-based compounds
- carbon is the best element for building large, complex molecules
- all molecules that distinguish living matter are carbon compounds
44
tetravalence
an atom with four "empty" valence electron "spots"
45
carbon atoms form diverse molecules
- electron configuration determines the kinds and number of bonds an atom will form with other atoms
- with four valence electrons, carbon can form up to four covalent bonds with a variety of atoms
- this tetravalence makes large, complex molecules possible
46
hydrocarbons
molecule consisting only of carbon and hydrogen, they are nonpolar (because carbon's and hydrogen's electronegativites are very similar)
47
what are biological molecules made from
hydrocarbon frames and have functional groups that can make the molecules polar
48
most hydrocarbons have many what kind of bonds
covalent
49
carbon molecular diversity
carbon chains vary in length and shape (because of tetravalence)
50
why is carbon so necessary for life?
1. form stable bonds with many elements, including itself
2. form a huge variety of very large complex molecules
3. carbon is small enough to form bonds with other carbons (making chains) and to form bonds with other atoms
51
what is hydroxyl found in
carbohydrates, proteins, nucleic acids, lipids
52
what is carboxyl found in
proteins, lipids
53
what is amino found in
proteins, nucleic acids
54
what is phosphate found in
nucleic acids
55
what are biological macromolecules
carbon based molecules
56
what are the 4 classes of biological macromolecules
- carbohydrates
- lipids
- proteins
- nucleic acids
57
how do macromolecules build up and break down
metabolism
58
metabolism
- refers to all of the chemical reactions that occur in a cell
- this includes anabolic and catabolic reactions/pathways
- anabolic reactions/pathways BUILD complex molecules from simpler molecules
- catabolic reactions/pathways BREAK down complex molecules into simpler molecules
59
macromolecule structure
most macromolecules (such as nucleic acids) are polymers
60
monomers
the small building-block molecules
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polymer
a long molecule consisting of many similar building blocks
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anabolic pathways
- the synthesis (making) of complex molecules from simpler molecules
- "building up"
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polymers are built through...
anabolic pathways
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what is the specific reaction of a polymer
condensation reaction (aka dehydration synthesis)
65
when does condensation/dehydration synthesis occur
when two monomers join as they lose a water molecule
66
enzymes
macromolecules that speed up the anabolic process
67
catabolic pathways
- the breakdown of complex molecules into simple molecules
- "breaking down"
68
to break apart a polymer
- catabolic pathways
- hydrolysis: a reaction that disassembles polymers to create monomers
- a reaction that is the opposite of dehydration synthesis
69
what is hydrolysis
hydro- water // lysis- split
70
how to remember anabolism vs catabolism
ana builds, the cat breaks
71
nucleic acids - basic structure
- monomer: nucleotide
- polymer: polynucleotide :nucleotides are connected together by phosphodiester bonds in a polynucleotide :a polynucleotide strand has direction
- function: store, access, and transmit genetic information
- 2 examples: DNA, RNA
72
pentose sugars
there are two types of pentose sugars that are found in nucleotides
- deoxyribose
- ribose
the difference is that deoxyribose lacks an oxygen on the 2' carbon (just a -H instead of an -OH)
73
nucleotide structure
3 parts
- phosphate group
- 5 carbon (pentose) sugar
- nitrogen base
elements
-C, H, O, N, and phosphorus
74
DNA nitrogen bases
Adenine with Thymine, Guanine with Cystosine
75
RNA nitrogen bases
Adenine with Uracil, Guanine with Cytosine
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purines
2 rings
A & G
77
pyrimidines
1 ring
C & T & U
78
are DNA strands antiparallel or complimentary
antiparallel
79
what does DNA stand for
deoxyribonucleic acid
80
if a nucleotide is a "generic nucleotide", what should you name it?
pentose sugar
81
if you are labeling a DNA nucleotide, what would you label it?
deoxyribose
82
if you are labeling an RNA nucleotide, what would you label it?
ribose
83
what holds the 2 strands together in DNA
hydrogen bonds
84
how are nucleotides connected
phosphodiester bonds
85
what is a hydrogen bond
it is a weak attraction between a slightly positive hydrogen, and a slightly negative atom
86
what do you call the pairings A & T and C & G
complementary base pairing
87
purine + purine + ?
too wide (A/G pair)
88
pyrimidine + pyrimidine = ?
too narrow (C/T pair)
89
purine + pyrimidine = ?
width consistent with x-ray data
90
hydrogen bonds compatibility
it is like puzzle pieces, the hydrogen bonds have to line up and be compatible
91
carbon labeling
gives us a way to talk about the ends of the strands since they are different
92
how are carbons in the sugar labeled
1', 2', 3', 4', and 5'
1' is attached to the bast, and the 5' carbon is attached to the phosphate group (counterclockwise)
93
where was genetic material found
in the nucleus of eukaryotic cells
94
where are the 2 biological macromolecules that are found in the nucleus
nucleic acids and protein
95
why did scientists initially think that proteins were the genetic material
there are over 20 different amino acids (monomers of proteins) and only 4 different nucleotides in DNA
96
who were hershey and chase
they studied bacteriophages and knew that they infect bacteria by injecting their genetic material as well has containing a protein shall and nucleic acid core
conclusion: confirmed that DNA was the genetic material because it was injected into the bacterial cells
97
who is chargaff
look at the proportions (%) of the different bases in DNA of different species
98
what were chargaff's 2 major conclusions
1. different species have different % of each base
2. in any species:
- the amount of adenine was roughly equal to the amount of thymine (A = T)
- the amount of guanine was roughly equal to the amount of cytosine (C = G)
A + G = T + C
99
who is rosalind franklin
- used x-ray crystallography to take images of DNAA
- photo 51 showed that DNA was a double helix
- rosalind didn't want to share her finding without additional evidence
wilkins (also had to work on DNA imaging) shared photo 51 with james watson without rosalinds knowledge
100
who are watson and crick
- used rosalind's research and cargaff's data to create the double helix model of DNA
- published a paper in nature in 1953
101
why did rosalind franklin not receive the nobel piece prize
- in 1962, watson, crick, and wilkins were awarded the noble piece prize in physiology or medicine for their discovery of the structure of DNA
- rosalind franklin died in 1958, so she did not receive the noble prize for her contribution to this discovery
