Test 1 Flashcards
1
Q
What does the scientific method require and how do we achieve it
A
requires objectivity (unbias) and we achieve it through peer review where the research is assessed by experts who have no direct involvement
2
Q
observational studies can be…
A
descriptive or analytical
3
Q
controlled experiemnt
A
treatment group and control group: treatment group has a change in one variable and the same variable is constant in control group
4
Q
double blind
A
neither researcher or patient knows if theyre getting placebo
5
Q
living organisms are..
A
- are composed of one or more cells
- reproduce using DNA
- obtain energy from their environment to support metabolism
- sense their environment and respond to it (dog in a thunderstorm)
- maintain constant internal environment (homeostasis)
- can evolve as groups
6
Q
a cell
A
a self contained unit enclosed by a water repellant layer called the plasma membrane
-came from a pre-exisitng cell
7
Q
bacterium
A
an example of a single celled organism
8
Q
multicellular organisms
A
composed of many different specialized cells working together
9
Q
dna
A
is stored within a membrane bound nucleus
10
Q
a gene
A
a segment of dna that codes for a specific genetic trait
11
Q
differentiation
A
express some genes and suppresses other genes/characteristics
12
Q
producers
A
obtain energy from the nonliving part of their environment
13
Q
biological evolution
A
a change in the overall genetic characteristics in a group of organisms over the generations
14
Q
artificial selection
A
evolutionary change caused by humans; it occurs when we select plants and animals with preferred traits (dog breeding)
15
Q
domains
A
bacteria, archaea, eukarya
16
Q
Isotopes
A
same element that exists in variant forms that differ in their atomic mass
17
Q
Covalent bonds
A
form by electron sharing between atoms
18
Q
ionic bonds
A
form between atoms of opposite charge
19
Q
special properties of water
A
- its a polar molecule (slightly positively charged and partially negatively charged ( H+ O-)
- water is a solvent for charged or polar substances
- hydrogen bonding accounts for the physical properties of liquid water and ice
- water moderates temperature swings
- the evaporation of water has a cooling effect
- hydrogen bonding accounts for the cohesion of water molecules
20
Q
what provides the framework for life
A
carbon
21
Q
Functional group have..
A
distinct chemical properties
22
Q
Proteins are
A
- built from amino acids (20 different ones)
- must be folded correctly to be functional
- covalently linked
- strings
- side chains make a certain protein (functional group)
23
Q
What do animals do with surplus energy
A
they store them as triglycerides
24
Q
what are important components of cell membranes?
A
phospholipids
25
biomolecules
- molecules that are unique to living cells
| - carbon based: they have a backbone of carbon atoms
26
what is matter
anything that has mass and occupies space
27
how many different types of matter are there
92 that occur naturally in our universe
28
what is an element
a pure substance
29
metals, nonmentals, and electrons
metals can lose electrons
| nonmetals take/grab electrons
30
Metalloids
have some properties that are like metals and some that arent
31
Carbon is
abundant in living cells but scarce in nonliving matter
32
what do atoms contain?
a unique combination of protons, electrons, and neutrons
33
protons have
a positive charge
34
electrons have
have a negative charge
35
neutrons are
neutral
36
how do negative electrons move around the nucleus
in electron shells
37
what does the atomic number represent
the number of protons in an atom
38
what does the atomic MASS number represent
total number of protons and neutrons in an atom
39
Isotopes in reference to electrons, protons, and neutrons
isotopes of an element have the same number of protons and electrons but differ in the number of neutrons
40
formula to figure out how many neutrons an element has
mass - atomic number = neutrons
41
what is the fixed number of e- in any atomic shell is fixed
2, 8, 8 in 1st, 2nd, 3rd shell
42
what happens when the outermost shell is filled to capacity?
an atom is most stable
43
What happens when an atom loses one or more electrons?
it becomes a positively charged ion
44
What happens when an atom gains one or more electrons?
it becomes a negatively charged ion
45
non polar molecules are
not soluable in water
46
what are molecules that do not associate with water?
hydrophobic
47
PH (acidic vs basic)
-Less than 7 is acidic
-more than 7 is basic
a ph that is 1 less than the other amount is 10 times more acidic ex. PH of 3 is 10 more acidic then a PH of 4
-water has a PH of 7 (neutral)
48
a buffer
is a combination of chemicals that maintains PH
| -it maintains PH by accepting hydrogen ions when too acidic and releasing when too basic
49
organic molecule
is one that contains at least one carbon hydrogen bond
50
many monomers make what
a polymer
51
proteins functions
- storage
- structure
- transport
- catalyst
52
proteins structure
1. primary structure
2. secondary structure
3. tertiary structure
4. quaternary structure (hemoglobin)
- if you change one amino acid, the whole structure falls apart
53
what is a fatty acid
a hydrophobic chain attached to hyrdophillic head
54
what are all single bonds
saturated fatty acids
55
what are double covalent bonds
unsaturated fatty acids
56
if the molecules pack easily it is
solid
57
if the molecules unpack easily it is
not solid
58
how do atoms with an unfilled outermost shell achieve stability?
by sharing electrons to fill their outermost shell to capacity, forming a molecule in the process
59
Covalent bonds and number of bonds
- one covalent bond: one pair of electrons shared between 2 atoms
- double covalent bond: two pairs of electrons shared
- triple covalent bonds: three pairs of electrons shared
60
what are molecules
two or more atoms that share electrons to form a chemical bond known as a covalent bond (can have same elements or different elements)
61
how are salts held together
by ionic bonds
62
what makes one end of a polar molecule more negative and the other more positive
uneven distribution of electrical charges
63
hydrogen bond
a weak attraction between a hydrogen atom with a slight positive charge and a neighboring atom with a slight negative charge
64
nonpolar molecules
NOT SOLUABLE in water bc water molecules cannot surround them in a hydrogen bonded network
65
in plants what does cellulose do
it stregthens plant cell walls
66
how do plants store surplus energy
in the form of startch
67
Denaturation of proteins.. what happens?
the three dimensional shape is destroyed by extreme temperatures, PH, and salt concentration
68
what are saturated fatty acids
fatty acids in which carbon atoms are linked with a single covalent bond
69
what are unsaturated fatty acids
fatty acids are linked by a DOUBLE covalent bond
70
how do organisms store their surplus energy
as triglycerides
71
what are phospholipids
- a type of glyceride
- main component of cell membrane
- form a phospholipid bilayer
- in very warm environment they melt, in cold they stiffen
72
phospholipid bilayer
hydrophillic heads face outward and the hydrophobic tails tuck into the interior
73
what are sterols
a class of lipids that contain four hydrocarbon rings fused to each other (cholesterol, testosterone)
74
what are lipids
fatty acids, phospholipids, and sterols
75
DNA vs RNA
dna is double stranded and rna is single stranded
| Nucleic acids are AGCT (U) with RNA
76
What are prokaryotes?
they are bacteria and archaea, both single celled organisms
77
All members of the plant and animal kingdom are what?
multi cellular
78
What does the cytoplasm contain?
a thick fluid called cytosol, consisting of ions of biomolecules mixed in water
79
what is an organelle?
a cytoplasmic structure that performs a unique function in the cell
80
In eukaryotes, where is DNA?
DNA is enveloped inside the double membranes of the nucleus
81
what does the mitochondira do?
- provides the energy (ATP) that fuels all cellular functions
- it extracts energy from food molecules, releasing carbon dioxide and water in an oxygen dependent process called cellular respiration
82
What are ribosomes?
they are important protein manufactoring organelles
83
How does the cell exchange materials?
across the cell surface - the larger the cell surface area, the more efficient
84
relationship between cell volume and metabolic capacity
-the greater the cell volume the higher the metabolic capacity of the cell
85
cell size and surface area to volume ration
-if a cell is large it has a lower surface are to volume ratio than a smaller cell
86
what is a multicellular organism?
-it consists of an interdependent group of genetically identical cells that developed from a single cell. They can't live independently
87
benefits of a multicellular organism
- better odds of escaping predators that are smaller
- better odds of capturing prey that are smaller
- more space to store food and other nutrients
- efficient functioning through division of labor among differentiated cells
88
What is the plasma membrane
- it is a selectively permeable barrier (only certain things can go in) which ensures that the cell interior is chemically different than the extracellular environment
- the membrane is composed of a phospholipid bilayer with embedded proteins
89
what is the plasma membrane responsible for
- capturing needed molecules and bringing them into the cell
- removing waste from the cell
- communicating with other cells and the environment
- anchoring the cell in place
90
what are biological membranes
they are a fluid mosaic, many components (lipids/proteins) move freely in the plan eof the phospholipid bilayer
91
what do membrane proteins do
they enable transport (nutrients/waste) communication with external environment and attachment to extracellular matrix and neighboring cells
92
What is the cellular organization in prokaryotes
- DNA not bound in membranes (no nucleus)
- much smaller than eukaryotic cell
- most have tough polysaccharide cell wall
- internal compartments lacking or much less complex
93
Adapative benefits of eukaryotic cells
- efficient functioning via intracellular division of labor (specialized compartments)
- concentration of necessary reactants for chemical reactions
- maintaining special environments
- isolating damaging by products of metabolism
94
what kind of nucleus does a eukaryotic cell have
- a nucleus bound by a double plasma membrane called the nuclear membrane
- the nucleus contains DNA required for building, managing, growing, and reproducing cells
95
what are nuclear pores
- the nuclear envelope contains nuclear pores through which ions and small molecules pass freely
- passage of larger molecules and proteins is regulated by nuclear pores
96
what does RNA do
- it carries directions for making proteins from the DNA in the nucleus to the ribosomes in the cytosol
- RNA molecules exit through the nuclear pore to direct protein synthesis on ribosomes
97
What is the endoplasmic Reticulum
it is an interconnected network of tubes and flattened sacs that produces certain lipids and proteins
98
What is the Rough ER
it is dotted with ribosomes that produce proteins for use both inside and outside the cell
99
What is the ER's Function?
it functions like a specialized department, preparing items for transport to other parts of the cell or export outside the cell
100
what is the smooth ER
enzymes of the smooth er produce lipids for other cellular compartments and help break down toxic organic compounds in the cell
101
what is a transport vesicle
it is a small, spherical, membrane enclosed sac that moves lipids, proteins, and carbohydrates between cellular compartments
102
how does the transport vesicle deliver its contents?
it fuses with the membrane of the target destination
| -the molecules are being shipped from the ER to the Golgi Apparatus
103
what does the golgi apparatus do
it directs proteins and lipids produced by the ER to their final destination, either inside or outside the cell, through the addition of specific chemical groups
104
what do the vesicles do?
they move the lipids and proteins from the ER to the Golgi Apparatus and then to other destinations in or outside the cell
105
what are lysosomes
they contain enzymes that break down macromolecules, releasing the subunits into the cytoplasm for recycling or waste removal
-they are found in animal cells
106
what is the interior of the lysosome like?
it is highly acidic, with a PH of 5
107
what are plant vacuoles?
- they act like lysosomes to break down macromolecules
- they also store ions and water soleuable molecules such as coloful pigments
- they can also store noxious chemicals adn release them upon damage to deter herbivors
108
what do vacuoles with water do?
they provide tugor pressure which helps make the nonwoody parts of the plant cells stiff
109
what does the inner membrane do?
-it creates a large surface area with room for many ATP generating enzymes
110
what is the cristae and how is it formed?
- the folds of the inner membrane form the cristae
| - the folding of the cristae creates a large surface area for locating the components of the respiratory reactants
111
how do plants use chloroplasts?
they use them to capture energy from sunlight to make sugars in a process known as photosynthesis
112
what is a by product of photosynthesis?
oxygen which sustains life for humans and many other organisms
113
what do chloroplasts have?
they have two outer membranes and an extensive network of internal membranes that contain a green pigment aka chlorophyll
114
what does chlorophyll do
it absorbs red and blue wavelengths of light (reflects green) and the absorbed energy is used to split the water molecule, generating energy carriers (ATP) that fuel the synthesis of sugars from carbon dioxide and water
115
what is the cytoskeleton (eukaryotic cells) and what does it consist of
- it consists of filaments and cylinders of filaments and cylinders of special proteins that constitute an internal framework within the cytoplasm
- it supports the movement of organelles, stregthens cell membranes, and can enable movement
116
what are microtubles and what are they used for
- they are rigid, hollow, cylinders of protein
- they are used for positioning organelles, moving transport vesicles and other organelles, and generating force to propel the cell
- guide organelles to their destination within the cell
117
what are intermediate filaments
they are ropelike cables of protein that provide mechanical and structural reinforcement/support to the cell
118
what are microfilaments
- they are thin, flexible proteins (actin) that create cell shape and generate crawling movements in some cells
- they can lengthen and shorten to create movement in the cell
119
what is the nuclear membrane supported by?
intermediate filaments
120
what does cell crawling in microfilaments do?
- it enables amoebas and slime molds to find food and mating partners
- wound healing and embryonic development both rely on cell crawling
121
what do cilia do?
- they enable whole cell movement
- they can move back and forth to move a whole cell through liquid or to move a liquid over the surface of a stationary cell
122
what are inside cillium?
microtubles interlinked with motor proteins change shape using energy from ATP
123
Eukaryotic Flagella
- bacteria, archaens, protists, and sperm cells use flagellum to propel themselves through fluid
- move in a whiplike fashion
124
Prokaryotic Flagella
- they differ from eukaryotic flagella in structure and movement
- they lack microtubles, are NOT covered by the pasma membrane, spin like a boats propeller
125
how did the eukaryotic cell evolve?
- it was a large predatory cell that engulfed prokaryotic cells
- mitochondria and chloroplasts are believed to have been free living prokaryotes that were engulfed
- mutualism between the engulfed prokaryote and the host cell led to the organelles (mitochondria)
126
what do transport proteins do?
they span the width of the plasma membrane and provide pathways by with specific materials can enter or leave
127
how do cells maintain the chemical balance between the interior and exterior of the cell
they expend a large amount of energy
128
what is passive transport
the spontaneous movement of a substance and without the input of energy
129
what is active transport
the movement of a substance with input of energy
130
what is diffusion
the passive transport of a substance from a region of higher concentration to lower concentration
131
how is equilibrium reached
when concentration gradients disappeaer
132
what makes the rate of diffusion higher
higher temperature, higher difference in concentration, faster they move,
133
what is osmosis
diffusion of water molecules from high concentration to low concentration across a selectively permeable membrane
134
what is a hypotonic solution
lower solute concentration than the cytosol of a cell, which causes water to flow into the cell and make it swell
135
what is a hypertonic solution
has a higher solute concentration than the cytosol of cell which causes water to flow out of the cell and make it shrink
136
what is an isotonic solution
equal concentration of a solute
137
what is simple diffusion
when small molecules can cross cell membrane without assistance
138
what is facilitated diffusion
passive movement of a sbustance with the assistance of membrane transport proteins
139
what are the membrane transport proteins
- channel proteins
| - carrier proteins
140
what are channel proteins
they move substances down a concentration gradient, without an energy input based on size, shape, and chemical characterisitcs
141
what are carrier proteins
they transport molecules across the plasma membrane based on the shape of the molecule,
142
what are the two types of carrier proteins
- passive carrier proteins: assist in diffusion of molecules from high concentration to low concentration
- active carrier proteins: use ATP to pump ions or molecules across the membrane against a concentration gradient
143
what is exocytosis
substances to be exported from a cell are packaged into transport vesicles that fuse with the plasma membrane to expel the contents
144
what is endocytosis
brings substances into the cell by wrapping them in a section of the plasma membrane
145
What are the types of endocytosis
- pinocytosis (nonspecific, brings in all the material in an immediate area)
- receptor mediated endoytosis (specialized receptor proteins determine which substances are incorportated into the vesicle)
- phagocytosis (ingests large particles and destroy foreign substances)
146
how does cholesterol form LDL particles in the blood?
it is hydrophobic so it is packaged with proteins to form LDL
147
what are cell junctions
they are plasma membrane structures that link cells to their surroundings
148
whats a tight junction
belts of proteins that create leak proof sheets
149
whats an anchoring junction
form patches of proteins that link cells that typically undergo heavy structural stress
150
what are gap junctions
- they are connections between the cytoplasms of cells that span the intercellular space between adjacent cells
- they facilitate the rapid passage of ions and small molecules between adjacent cells
151
what are plasmodesmata (plant cells)
- tunnels through the cell wall that connect the plasma membranes and cytoplasm of adjacent cells
- they enable rapid communication between plant cells
152
what is a target cell
recieves a signal through receptor protein loacted on the plasma membrane or in the cytoplasm and the singal is then relayed internally
153
cholesterol in cell membranes
is found in the cell membranes and plugs the space between phospholipids to make them less leaky
