BIOLOGY Flashcards
(103 cards)
1
Q
anion
A
negative ion (atom that gains electrons)
2
Q
cation
A
positive ion (atom that loses electrons)
3
Q
Properties of Water
A
- water has high specific heat (amt of energy that must be absorbed to increase 1 gram by 1 degree celsius
- high heat of vaporization
- universal solvent
- strong cohesion tension (strong attraction to one another)
- moving up tree trunks with out energy
- capillary action (cohesion and adhesion)
- surface tension
- ice floats because its less dense than water
4
Q
pH
A
pH= -log [H+]
common pH values
stomach = 2
blood = 7.4
5
Q
Isomers
A
organic compounds that have same molecular formula but different structures
6
Q
types of isomers
A
structural isomer - differ by arrangement of atoms
cis-trans - differ by spatial arrangement of double bonds
enantiomers - differ by mirror images of each other
(left handed (L) or right handed (D) versions)
ALL AA are left handed
7
Q
4 major organic compounds
A
carbohydrates, lipids, proteins, nucleic acids
8
Q
3 classes of carbs
A
monosaccharides, disaccharides, and polysaccharides
9
Q
monosaccharides
A
glucose, fructose, galactose (C6H12O6) – all 3 are isomers of each other
10
Q
polysaccharides
A
many monosaccharides formed together
cellulose = beta-glucose starch = alpha glucose chitin = beta glucose w/nitrogen glycogen = alpha-glucose with branching
11
Q
fatty acids
A
exists as saturated or unsaturated (has double bonds)
12
Q
saturated fats
A
solid at room temperature, linked to heart disease (butter)
13
Q
unsaturated fats
A
extracted from plants, liquid at room temperature, have at least one double bond
14
Q
steroids
A
four fused rings
15
Q
Protein structures
A
primary- linear sequence of AA
secondary - alpha helix or beta pleated sheets (held by H bonds)
tertiary- H bonds, ionic bonding with R groups, hydrophobic interactions, Van der Waals, disulfide bonds between cysteiene AA
quaternary - consists of more than one polypetide chain (i.e. Hb)
16
Q
-delta G
A
exothermic
17
Q
+delta G
A
endothermic
18
Q
catabolism
A
break down of molecules
19
Q
anabolism
A
build up molecules
20
Q
induced fit model
A
substrate enters enzyme (tertiary structure) to alter its shape slightly to fit the substrate better
lock and key was abandoned because it falsely implied that the enzyme does not change
21
Q
theory of endosymbiosis
A
eukaryotic cells emerged from mitochondria and chloroplasts
22
Q
prokaryotes
A
no membrane bound organelles, circular naked DNA, small ribosomes, anaerobic or aerobic metabolism, no cytoskeleton, mainly unicellular, 1-10 micrometers
23
Q
eukaryotes
A
membrane bound organelles, DNA wrapped with histone proteins into chromosomes, larger ribosomes, aerobic metabolism, multicellular, 10-100 micrometers
24
Q
nucleolus
A
rRNA is synthesized, non membrane bound, a tangle of chromatin and unfinished ribosomal products
25
ribosomes
they synthesize proteins--found free in the cytoplasm (proteins used for cell) or bound to the ER (proteins sent out)
26
peroxisomes
contain catalase which converts hydrogen peroxide (H2O2) into water with release of O2 atoms (a product of respiration in the cell
they also detoxify alcohol in liver cells
27
nucleus
contain chromosomes, surrounded by selective nuclear envelope--has pores that transport mRNA
28
Endoplasmic Reticulum
RER - studded with ribosomes and produces proteins to transport out of the cell
SER - assists in synthesizing steroid hormones (sex hormones), stores Ca2_ ions in muscle cells to help with muscle contraction, detoxifies drugs and poisons from the body
29
Golgi Apparatus
lies near nucleus that process and package substances produced in the RER and secrete the substances to other parts of the cell or cell surface for export
30
Lysosomes
sacs of hydrolytic (digestive) enzymes --used for intracellular digestion
used in apoptosis
NOT FOUND IN PLANT CELLS
31
Mitochondria
site of cellular respiration, has outer and inner membrane (called Cristae), contain its own DNA,
32
vacuoles
membrane bound structures used for storage-- vesicles derived from ER and golgi apparatus
plant/protist vacuoles have contracting ability to pump water out
food vacuole are formed by phagocytosis of foreign material
33
Chloroplasts
contain green pigment (chlorophyll), absorbs light, synthesizes sugar
contain outer membrane and inner membrane (thylakoids)
34
cytoskeleton
protein filaments that extends throughout the cytoplasm
- maintain cell shape
- controls position of organelles
- controls flow of cytoplasm
- anchors cell in place by interacting with extracellular environment
contain microtubules and microfilaments
35
microtubules
hollow tubes that make up cilia, flagella, spindle fibers
36
cilia and flagella
made up of 9 pairs of microtubules and 2 singlet microtubules
37
microfilaments
assembled from actin filaments and support shape of cell
animal cells form cleavage furrow during cell division
ameoba to move by sending out pseudopods
skeletal muscle contract as they slide along myosin filaments
38
MTOCs
centrioles, centrosomes, or microtubule organizing centers (MTOCs) -- organize spindle fibers for cell division
39
Cell wall
in plant cells, lamella is area between two plant cell walls
40
pinocytosis
cell drinking, the uptake of large dissolved particles-- particles are engulfed by plasma membrane
41
phagocytosis
engulfing large particles or small cells by pseudopods
42
gap junctions
direct contact in animal cells
43
plasmodesmata
direct contact in plant cells
44
aerobic respiration
highly exergonic, releases energy
glycolysis followed by Citric acid cycle (Krebs), ETC and oxidative phosphorylation
45
anaerobic respiration
glycolysis followed by alcoholic fermentation or lactic acid fermentation
46
Reduction
gain of electrons or hydrogen H+
47
oxidation
loss of electrons or protons
48
glycolysis
breaks down 1 molecule of glucose into 2 three carbon pyruvate (releases 4 molecules of ATP) -- but uses 2 ATP to start the process
occurs in cytoplasm (without Oxygen)
ATP produced by substrate level phosphorylation (direct transfer of phosphate to ADP
*when there is enough ATP, ATP inhibits Phosphofructosekinase (PFK) -- enzyme required in glycolysis
49
pyruvate
3 carbon molecule that is product of glycolysis but starting point for aerobic respiration (Kreb cycle)
50
mitochondria
krebs cycle takes place in matrix
ETC takes place in Cristae
proton concentration builds up in outer compartment
51
Citric Acid cycle
- pyruvate combines with Coenzyme A to form acetyl-CoA
- this conversion gives us 1 NADH (2 total because two pyruvates)
- Acetyl CoA combines with oxaloacetic acid (OAA) to produce citric acid
- each turn of the Kreb cycle produces 2 NADH, 1 ATP, 1 FADH, CO2 (total of two turns for two pyruvates)
- during kreb cycle, ATP is produced by substrate level phosphorylation (direct transfer of phosphate to ADP)
52
NAD+ and FAD (oxidized)
NADH and FADH2 (reduced coenzymes) -- carry protons and electrons from glycolysis/Kreb cycle to ETC
53
electron transport chain
proton pump in mitochondria (located in cristae) that couples exergonic and endergonic reactions
uses energy released from exergonic flow of electrons to pump protons against its gradient from the matrix to the outer compartment
--overall establish proton gradient in mitochondria
final electron acceptor is oxygen (highly electronegative oxygen pulls electrons through the ETC) -- forms water as waste product
ETC consists of cytochromes
NADH produces 3 ATPs, FADH2 produces 2 ATPs
54
Oxidative phosphorylation
chemiosmotic theory - uses potential energy stored in form of proton H+ gradient to phosphorylate ADP to ATP
proton gradient created between outer compartment and inner matrix
protons can only flow down its gradient thru ATP synthase channels which generate energy to phosphorylate ADP to ATP
55
Facultative anaerobes
tolerate oxygen, but don't have to use it
56
obligate anaerobes
can not live in area with oxygen
57
alcohol fermentation
cell converts pyruvate to ethyl alcohol and CO2 (in the process oxidizing NADH to NAD+) -- this is required for glycolysis to accept electrons/protons to continue living
58
Lactic Acid fermentation
pyruvate from glycolysis is reduced to form lactic acid or lactate (which also oxidizes NADH to NAD+)
lactic acid is converted back to pyruvate in the liver (in muscle cells)
59
Light-dependent reaction
use light energy directly to produce ATP that powers the light independent reaction
60
Light-independent reaction
consists of Calvin cycle to produce sugar
Calvin cycle uses ATP from light reactions to power production of sugar
61
Two major pigments found in plants
cholorphylls and carotenoids
62
Chlorophyll a and chlorophyll b
both are green and absorbs all wavelengths of red, blue, and violet
63
Caretenoids
are yellow, orange, red -- and absorb light in blue, green, violet
64
Xanthophyll
another plant pigment-- like a caretenoid with slight chemical variation
65
Phycobilins
found in red algae. red color and absorb blue and green
66
Chlorophyll b and cartenoids
"antennae pigments- capture other wavelength of lights different from chlorophyll a" -- absorb photons of light and pass the energy along to chlorophyll a, which is directly involved in transforming light energy to sugar
67
mitosis
produces two genetically identical daughter cells
```
consists of PMAT
prophase
metaphase
anaphase
telophase
```
68
Meiosis
sexual reproducing organisms that results in cells the are haploid (half the # of chromosomes of the parent cell (n))
69
sister chromatids
two exact copies of each other
70
centromere
specialized region that holds two chromatids together
71
kinectochore
disc-shaped protein on the centromere that attaches the chromatid to the mitotic spindle during cell division
72
two factors that limit cell division
1) ratio of volume of cell to surface area
- SA increases at square of radius
- Volume increases at cube of radius
- volume increases faster and nutrients is based on transport of the SA cell membrane (determinant in when cell divides)
2) capacity of the nucleus to control entire cell
73
Phases of Cell cycle
G1, S, G2 (G1,S,G2 all make up interphase), mitosis, cytokinesis
74
interphase composed of?
G1,S,G2 (90% of cell life is spent in this phase)
at G2-M transition, a single centrosome is duplicated and separated to opposite poles for cell division
(plants lack centrosomes--but have MTOCs) microtubule organizing centers
75
G1
period of intense growth/biochemical acitivity
76
G2
cell continues to grow and complete preparations for cell division
77
Prophase
nuclear membrane dissolves
chromosomes condense (no longer thread-like)
nucleolus disappears
in cytoplasm, mitotic spindle begins to form, connecting one centrosome to the other
78
Metaphase
CHROMOSOMES LINE UP on metaphase plate
centrosomes at opposite poles
spindle fibers connect centromere to kinetochore to centromere
79
centrioles, centrosomes, centromeres
Centrosomes: These are the organizing centers for the microtubules that appear in prophase and then move to the polar ends of the cell.
Centromeres: The part of the chromosome where the DNA is wound tighter than the other DNA giving an indention look to it. It is also a great way of counting chromosomes.
Centrioles: These are found near the centrosomes, usually at right angles, that act in microtubule formation.
Kinetochore: These lie on the centrosomes of the chromosomes and is where the mitotic spindle connects to.
Mitotic Spindles: These are macromolecular machines that pull chromosomes apart during anaphase.
80
Anaphase
centromeres of each chromosome separate as spindle fibers pull apart sister chromatids
81
Telophase
nuclear membrane reforms as chromosomes cluster at opposite poles
condensed chromosomes unravel
mitosis complete after two nucleoli form
82
Cytokinesis
dividing of the cytoplasm -- occurs during anaphase
animal cells form "cleavage furrow" - when actin/myosin filaments pinch in the cytoplasm
in plants, cell plates form during telophase-- cells do not separate, but a new cell wall forms and a sticky "middle lamella" connects the walls.
83
Contact inhibition (density dependent inhibition)
when cells divide to a point when it is too crowded and cells stop growing (inhibited at G zero) state
84
Anchorage dependence
cell must be attached/anchored to something to divide
cancer cells have no inhibition-- grows uncontrollably
85
Meiosis
produces gametes (ova and sperm)
contain haploid or monoploid chromosome number (n)
undergo division of nucleus twice
86
sexual reproduction
formation of two gametes (haploids) to form diploid again (2n)
87
Meiosis I
aka reduction division
```
- homologous chromosomes separate
Prophase I
Metaphase I
Anaphase I
Telophase I
```
88
Prophase I
Synapsis - paring of homologues (homologous chromosomes)
Crossing-over - exchange of homologous bits
Chiasmata - visible crossing over
89
metaphase I
pairs of homologues lined up in DOUBLE FILE (tetrads)
| spindle fibers attach to centromeres
90
Anaphase I
Separation of homologue chromosomes and pulled by spindle fibers and migrated to opposite poles
91
Telophase I
each pole has haploid number of chromosomes
92
Cytokinesis I
occurs with telophase I
93
Meiosis II
```
like mitosis
Prophase II
Metaphase II
Anaphase II
Telophase II
```
94
genetic variations of meiosis
independent assortment of chromosomes
crossing-over
random fertilization of ovum by sperm
95
Independent assortment of chromosomes
homologous pairs of chromosomes separate randomly at metaphase plate during metaphase I (2^23 combinations)
96
Cross-over
produce recombinant chromosomes that combine genes inherited from both parents
97
Random fertilization
one human ovum represents 8 million possible chromosome combinations
8 million x 8 million combos
98
Check points in cell cycle
Restriction Point (R) - G1 check point (most important) or arrested in G0 phase
G2 and M checkpoints
99
Mendel's First Law
Law of Dominance - states that two organisms, each homozygous for two opposing traits are crossed. The offspring will be hybrid but exhibit only one dominant trait
hidden train = recessive trait
100
Law of segregation
two traits carried by the parent separate (Tt) to T and t
101
Law of Independent Assortment
dihybrid cross produce 9:3:3:1
102
Pleiotropy
one gene to affect an organism in several ways (i.e. cystic fibrosis
103
epistasis
two separate genes control one trait, but one genes masks the expression of the other gene
