LS 2 midterm 1 Flashcards
1
Q
covalent bonds
A
two atoms share one, two, or three electrons –> very stable bond
most common
2
Q
ionic bonds
A
either give up or accept electron from another atom to achieve a filled outer shell
3
Q
hydrogen bonds
A
the attraction of the positive (hydrogen) end of the polar molecule to the negative end of another polar molecule (H - N,O,F) (high electronegativity)
4
Q
van der waals forces
A
weak interactions between atos due to movement of negatively charged electrons resulting in formation of dipoles – transient, but in large quantities can cause significant changes
5
Q
5 properties of water
A
- solvent - carries nutrients into body and wastes out; oxygen and CO2 can dissolve
- participates in chemical reactions - e.g. digestion
- absorbs and releases heat slowly - maintain homeostasis
- requires a large amount of heat to evaporate - perspiration can assist cooling of body
- provides lubrication - saliva, mucus because of cohesion and adhesion
6
Q
inorganic compounds
A
water, inorganic acids, bases, and salts
7
Q
organic compounds
A
carbs, lipids, proteins, nucleic acids
8
Q
property of inorganic acids, bases and salts
A
all undergo ionization (dissociation) when dissolved in water in the body
9
Q
how do acids ionize
A
produce hydrogen ions (protons) H+
10
Q
how do bases ionize?
A
release hydroxyl ions (OH-)
11
Q
how do salts ionize
A
cations and anions
12
Q
what is a cation
A
positive ion
13
Q
what is an anion
A
negative ion
14
Q
importance of inorganic salts in body
A
components of cells and body fluid – sodium and chloride ions in extracellular fluid and potassium and phosphate ions inside cells
15
Q
calculate pH
A
-logbase10[H+]
16
Q
what pH represents neutral
A
7
17
Q
what pH represent acidic
A
below 7 (1-7)
18
Q
what pH represents basic
A
above 7 (7-14)
19
Q
how does the body maintain constant pH (homeostasis)?
A
buffer systems
20
Q
what is a buffer
A
a solution of a weak acid or weak base which remove excess H+ ions and OH- ions
21
Q
pH of blood
A
7.35-7.45
22
Q
pH of gastric juice (stomach)
A
1.2-3.0
23
Q
types of lipids (4)
A
- fats (triglycerides)
- phospholipids
- prostaglandins
- steroids
24
Q
what are fats and their purpose
A
(triglycerides) consist of one glycerol and 3 fatty acids; serve as a source of energy, and protect and insulate
25
unsaturated fat
fatty acids have a double bond
26
saturated fat
fatty acids are all single bonds
27
difference between fat and oil
fat is solid at room temp and oil is liquid
28
what are phospholipids
components of cell (plasma) membrane -- lipid bilayer - polar head outside and nonpolar tail inside
29
what is amphipathic and example
polar and nonpolar parts - e.g. phospholipids
30
4 types of phospholipid movement
1. rotational (rapid)
2. diffusion (rapid)
3. flexion (rapid)
4. flip flop (rare)
31
rotational phospholipid movement
rotates along axis like a globe
32
diffusion phospholipid movement
lateral movement across bilayer (moves to diff spot in line)
33
flexion phospholipid movement
tails flex side to side
34
flip flop phospholipid movement
movement across bilayer, requires a special protein (moves to other side of bilayer)
35
what are prostaglandins
derivatives of fatty acids similar to hormones
36
what are fatty acids
chain of carbon atoms with a carboxyl group at one end
37
what are steroids
cholesterol is most abundant steroid in body and a component of cell membranes and steroid hormones are derived from cholesterol - ring structure
38
3 functions of carbohydrates
1. provide energy
2. form part of structural elements of some cells
3. supply carbon atoms for synthesis of cellular components
39
what is glycogen
carb - stored form of glucose in liver and skeletal muscles for rapid needs
a polysaccharide that is the man energy source for animals
releases branched polymer of glucose
40
types of carbs
monosaccharides, disacharides, oligosacharides, polysacharides
41
molar ratio of carbs
C:H:O 1:2:1
42
how does the H:O ratio in carbs compare to lipids
much lower
43
what are monosaccharides
simple sugars - one molecules
44
3 main types of monosaccharides
glucose, fructose, galactose
45
what are disaccharides
2 monosaccharides bonded
46
3 main types of disaccharides & how they're formed
sucrose, lactose, maltose (condensation reaction --> glycosidic reaction forms covalent bonds)
47
components of sucrose
glucose + fructose
48
components of lactose
glucose + galactose
49
components of maltose
glucose + glucose
50
what carb is milk sugar
lactose
51
what causes lactose intolerance
lack of enzyme lactase which breaks down lactose
52
what is an oligosaccharide
3-20 residues (sugars)
53
what is a polysaccharide and how can it be broken down
many monosaccharides bonded together (20+); broken down into constituent sugars by hydrolysis
54
what is cellulose
provides structural support to plants; unbranched polymer of glucose
layers of glucose that have H bond interactions
55
why is cellulose so strong
bc they lay flat and form h bonds between the layers
56
what are proteins and how are they linked
large complex molecules made up of amino acids, linked in sequence by covalent peptide bonds
57
what do amino acids consist of?
an amino group, carboxyl group, and a side chain
58
what is an amino group and it's pH
-NH2; basic
59
what is a carboxyl group and it's pH
-COOH; acidic
60
what is a side chain
the r group; different for each of the 20 different amino acids
61
5 roles of proteins
1. cytoskeleton - supports and organizes cell components
2. enzymes
3. transport and storage of small molecules
4. transmit info (hormones)
5. defend against infection (antibodies)
62
what percent of enzymes are proteins
only 95%
63
what is primary structure of proteins
the amino acid sequence
| - depends on specific amino acid at points along the chain and the number of amino acids making up the chain
64
what is secondary structure
local interactions
interactions between backbone
2 types:
alpha helices: corkscrew held together by hydrogen bonds
beta pleated sheets: protein chain loops back on itself (u-shape) like silk
65
tertiary structure
the 3d structure/conformation of the protein molecule, resulting from side chain interactions between different parts of the primary structure , all 4 types of bonds are possible e.g. hydrogen bonds, disulfide bridges between cysteine residues
66
quaternary structure
overall structure in a protein made up of more than one polypeptide chain (not all proteins have this)
interactions between multiple subunits of a protein
67
what structure is cholesterol
steroid ring structure
68
cholesterol is plants and animals?
absent from plasma membranes of most places, but present in up to 25% of lipid weight in plasma membranes of animals
69
do people need to consume cholesterol
no! body makes all cholesterol it needs in the liver
70
why is cholesterol needed
stabilizes the plasma membrane and helps produce bile salts for digestion
71
what happens if there's too much cholesterol
can lead to deposition of excess in the walls of arteries (leads to athlerosclerosis)
72
why is LDL cholesterol "bad"
carries cholesterol to the tissues for use by cells
73
why is HDL cholesterol "good"
carries the cholesterol back to liver for excretion
74
proteins involved in muscle movement
actin and myosin (myosin head group pulls actin globules)
75
what does it mean to denaturize a protein
unfold the protein until it randomizes
76
what are nucleic acids
long polymers made up of nucleotides
77
chemical difference between RNA and DNA
H is in DNA and OH is in RNA
78
sugar components of nucleotides
deoxyribose is in DNA and ribose is in DNA
| 5'-3' and 3'-5'
79
2 types of bases in nucleotides
purines and pyrimidines
80
purines
adenine, guanine
81
pyrimidines
cytosin, thyamine
82
complementary base pairs
adenine-thyamine and cytosine-guanine
83
3 types of RNA
```
messenger RNA (mRNA)
transfer RNA (tRNA)
ribosomal RNA (rRNA)
```
84
where does protein synthesis occur?
ribosomes
85
what is ribozyme
catalytic RNA, catalyst for making peptide bond between amino acids during protein synthesis
86
miller and Urey
synthesis of prebiotic molecules in an experimental atmosphere
87
types of tissue
epithelial tissue, coonective tissue, nervous tissue, muscle tissue
88
epithelial tissue
forms boundaries between parts of the body and has tight junctions keeping it sealed
89
connective tissue
cells in some sort of extracellular matrix
| e.g. bone in a calcified matrix, blood cells in plasma, adipose cell in triglycerous matrix
90
nervous tissue
neurons conduct and generate action potentials
91
muscle tissue
skeletal (bicep), cardiac, smooth (digestive tract)
92
prokaryotes
cells lacking a nucleus; e.g. eubacteria and archae bacteria
93
eukaryotes
contain a large, membrane bounded nucleus and DNA
| e.g. plants, animals, fungi, protists (algae)
94
size comparison between eukaryotic cells and prokaryotic cells
euk much larger than prok
95
polar amino acids
```
argenine
asparagine
glutamic acid
glutamine
histidine
lysine
serine
threonine
tyrosine
```
96
nonpolar amino acids
```
alanine
cycteine
glycine
isoleucine
methionine
phenylalanine
choline
tryptophan
valine
```
97
what happens during sickle cell anemia
mutation in beta subunit and part of protein becomes hydrophobic and causes aggregation of hb molecules into a sickle shape instead of usual biconcave
glutamine (P)--> valine (NP)
98
ideal total blood cholesterol
200 mg/dL
99
desirable LDL levels
less than 130 mg/dL
100
borderline high risk of athlerosclerosis LDL levels
130-159 mg/dL
101
high risk of athlerosclerosis LDL levels
160+ mg/dL
102
what kind of ratio of HDL:LDL do you want?
high ratio (more HDL)
103
difference in bases between DNA and RNA
DNA: G-C and A-T
RNA: G-C and A-U (no T)
104
2 types of microscopy
light microscopy and electron microscopy
105
characteristics of light microscopy
glass lense, uses visible light, magnified image
| resolution: 200 nm
106
characteristics of electron microscopy
electrons magnets focus a beam of electrons on specimens, more powerful, resolution 2 nm
107
types of light microscopy
bright field, phase contrast, stained and brightened, differential interference, fluorescence, confocal
108
bright field microscopy
light directly passes through cells; little contrast and few details
109
phase contrast microscopy
shows contrast by emphasizing differences in refractive index whih enhances light and dark regions and creates more contrast
110
stained and brightened microscopy
use a stain to enhance image
111
sample stains
eosin-- binds to + structures like proteins, collagens, and muscle tissue which turns it red/pink
hematoxelyn-- binds to negative structures like DNA and turns it blue/purple
112
differential interference microscopy
2 beams of polarized light enhance contrast
113
fluorescence microscopy
natural fluorescence; apply dye which will bind to different parts
114
confocal microscopy
uses fluorescent materials and autofocus light to create a clearer image
115
types of electron microscopy
transmission, scanning e-, freeze fracture
116
transmission electron microscopy
if absorbs e- will look darker and if e- pass through, it will look lighter
117
scanning e- electron microscopy
direct electrons to surface of sample and cause electron to be emitted where a screen catches them and produces a 3d structure
118
freeze fracture electron microscopy
freeze cells and use a knife to crack open frozen cells and the bumps are protein aggregates
119
purpose and method of cell fracturization/centrifugation
homogenizes cells
1. place in tube and centrifuge
2. particles form sediment pellet at bottom
* heavier particles sediment at lower speeds
120
centrifugation sediment times/masses
500 g for 10 min --> obtain nuclear fraction
10,000g for 20 min --> obtain mitochondria
100,000g for 1 hour --> get ER fraction
121
what did miller and urey do?
conducted an experiment where they simulated the conditions of early erath
122
what did miller and urey find from their experiment?
inorganic molecules could convert to important organic molecules and ultimately form life
123
describe miller and urey's experiement
heated a solution of gasses to simulate atmosphere of early earth, ran an electric current through it (like lightning), condensed it (like rain), and found amino acids, simple sugar, and other organic compounds
124
what is the "RNA World" hypothesis
in a world before dna for protein synthesis, rna was used as a carrier of genetic information and to catalyze reactions
125
theoretical process from RNA to DNA
start with rna (composed of ribose, bases, and phosphates) and some were replicable and eventually began to make catalytic proteins and eventually became double stranded DNA which survived because of the stability it provided for storage of genetic material
now: DNA uses RNA to make proteins
126
hierarchical organization of life
atoms --> molecules --> organelles --> cells --> tissues --> organs --> orga systems --> organization
127
5 properties of life
1. cellular organization
2. sensitivity/response to stimuli
3. growth
4. reproduction
5. homeostasis
128
are viruses alive?
no!
129
describe virus structure?
made up of a core of nucleic acids surrounded by a protein sheath (and sometimes a lipid envelope)
lack a cell membrane, nucleii, and organelles
can't reproduce on own --> need host cell to replicate
do not carry out metabolism on their own
130
what is cell theory
all organelles are composed of cells
cell is the basic building block of life --> all chemical reactions take place inside of cell
all cells arise through division of a pre-existing cell
131
why are cells so small
as object increases in size, volume increases more rapidly than surface area and cells need large SA:V ration in order to efficiently transport nutrients and waste
132
prokaryotes characteristics and examples
```
lack nucleus, DNA is coiled into a nucleoid
some have more than 1 nucleoid
small organism
dna is in direct contact with cytoplasm
E.g. eubacteria and archaebacteria
```
133
eukaryotes characteristics and examples
contains a large, membrane bound nucleus (containing DNA)
typically separated into many membrane bound compartments (organelles)
larger organisms
e.g. all plants, animals, fungi, protists
134
"special features" of prokaryotes (5)
1. cell walls (bacteria may have peptidoglycan in them)
2. outer membranes may enclose cell wall
3. cyanobacteria can cerry out photosynthesis
4. some may have flagella
5. some have pili (used for mating)
135
"special features" of eukaryotes (3)
1. plasma membranes, cytoplasm, ribosomes
2. internal cytoskeleton (maintains shape and moves materials around cell)
3. plants have cell walls and large vacuoles for storage of food, water, waste, nutrients, etc
136
sizes of plant cells
5-30 micrometers
137
sizes of animal cells
35-80 micrometers
138
sizes of prokaryotes
0.2-2 micrometers
139
endosymbiotic theory
explains origin of eukaryotic cels from prokaryotic cells -- states that some of the key organelles originated as a symbiotic relationship between 2 prokaryotes (one ingested other and eventually couldn't survive without)
140
what is the biggest organelle?
nucleus
141
what does the nucleus contain
most of the cells dna
142
how does the nucleus faciltate replication
DNA combined proteins form chromatin
chromatin condenses and coils tightly to form chromosomes connected by a centromere
mitosis to form 2 daughter chromosomes
143
what do chromosomes contain
contains one long molecule of dna - comprises many genes
144
what do ribosomes do
synthesize proteins (all cells synthesize them on ribosomes)
145
where are ribosomes located in eukaryotes (2 locations)
in the cytoplasm (free)
| bound to the rough ER
146
where do higher numbers of ribosomes go
energy producing organelles like the mitochondrial matrix and chloroplast stroma)
147
what are ribosomes made of?
ribosomal RNA associated with a proton
148
2 parts of the endomembrane system
1. golgi apparatus
| 2. endoplasmic reticulum (ER)
149
what is the ER
endoplasmic reticulum - extensive system of folded membranes
150
2 parts of the ER
rough ER
| smooth ER
151
characteristics of the smooth er
lacks ribosomes, site for glycogen hydrolysis, synthesis of steroids
152
characteristics of rough er
contains ribosomes, manufactures proteins for export from the cell and incorporate into membranes or to different organelles
153
what does the golgi apparatus do?
modifies, packages, and sorts proteins
| synthesizes some sugars/polysaccharides for the cell wall
154
how does the golgi synthesize sugars/polysaccharides
vesicles from the rough er fuse with the cis region of the golgi and secretory vesicles pinch off from the trans region
155
signal sequences operation
approximately 25AA residue long sequence at the beginning of a polypeptide chain directs the polypeptide chain to the ER and then it goes to the golgi and the secretory vesicle sends it out of the cell
156
example of signal sequence
insulin
157
how does insulin work
acts to decrease blood glucose by increasing glucose uptake in cells
the secretory vesicles are then exocytosed and stored in pancreatic beta cells until needed
158
what triggers insulin release
an increase in blood glucose - hyperglycemia
159
nickname for mitochondria
powerhouse of the cell
160
what do mitochondria do
convert energy from food to ATP
161
how are mitochondria sized
pretty small - similar in size to bacteria
162
what contains mitochondria?
almost all living things except those living in an environment without O2
163
where do most mitochindria exist
in metabolically active areas - heart, liver
164
what are plastids present in
plants and some protists like algae
165
what do plastids do?
carry out photosynthesis
166
structure of plastid membrane
double membrane without cristae; inner membrane forms stack of thylacoids (grana)
167
what is contained in thylacoid membranes
chlorophyll
168
what is stroma
fluid contained within the inner membrane of chloroplasts that suspends ribosomes, dna, elara
169
what are lysosomes
contain hydrolytic (digestive) enzymes, participate in phagocytosis
170
example of a pathology of lysosomes
tay sachs disease
171
what is tay sachs disease
harmful lipids known as gangliosides accumulate in dangerous quantities in the brains heme cells and the lysosomes cannot break down the compound
172
what are peroxisomes (in plants and animals)
accumulate toxic peroxides such as H2O2
| (byproduct of some biochemical reactions); and safely break it down without mixing with other parts of the cell
173
glyoxysomes
occur in plants and are similar to perixisomes
174
what are vacuoles
present in plant cells; store waste products and provide turgor
175
what replaaces lysosomes in plants
vacuoles provide similar role and turgor provided keeps plant rigid
176
what is the Cytoskeleton
maintains cell shape, facilitates cell movement
177
what is the Cell wall and where is it found
supports the cell's shape; present in plants, fungi and some protists (also present in bacteria)
178
what is the Extracellular matrix?
surrounds animal cells, and is composed of proteins eg. collagen,
glycoproteins, and proteoglycan
179
3 Components of the cytoskeleton
microfilaments, intermediate filaments, and microtubules
180
what are microfilaments?
strands of actin, involved in movement during animal cell division, and muscle contraction
181
3 uses for microfilaments
a. muscle contraction (myosin and actin interactions)
b. cytokinesis (division of cytoplasm)
c. microvilli (epithelial lining of small intestine); increase surface area for absorption
of nutrients across lumen across to the blood
182
what are intermediate filaments and an examples
tough, fibrous protein molecules twisted into rope-like structures which stabilize cell structure e.g. keratin in hair/nails
183
what are microtubules
involved in structure and function of cilia and flagella, centrioles, and movement of cellular organelles; important for the mitotic spindle;
184
microtubule uses
scaffolding
185
what is the sturcture of microtubules
hollow cylinders made of tubulin; made up of tubulin alpha and beta subunits- 13 subunits arranged in circle
186
what happens during depolymerization of microtubules
pull sister chromatids to opposite poles of cell
187
what are cilia
9 sets of microtubules arranged in spoke like pattern (9+2 pattern)
188
what are CENTRIOLES
microtubule organizing structure
189
what are Motor proteins and examples
use energy from ATP to use microtubules and facilitate movement of cell e.g. dynein and kinesin
190
how do flagella move?
Complex protein ring structures anchored in the plasma membrane form a motor unit that rotates the flagellum and propels the cell
191
how do Sister chromatids separate to form chromososmes
Mitotic spindle microtubules from opposite poles attach to each sister chromatid at the kinetochore in prometaphase. In anaphase, the connection between the sister chromatids breaks down and the microtubules pull the chromosomes toward opposite poles.
192
golgi apparatus cis region
lies closest to nucleus
193
where is the golgi apparatus trans region?
closer to cell surface
194
what act as the target for the signal sequences to latch onto
ribosomes
195
pH inside a lysosome
acidic - 5.5
196
what is autophagy
breaking down worn out cell organelles
| e.g. worn out mitochondria could fuse with a lysosome and be broken down
197
what are glyoxysomes
in plants, specialized form of peroxisomes; break down stored lipids
no lysosomes in plants
198
how do microfilaments participate in cytokinesis (division of cytoplasm)
occurs by loops of actin (microfilaments, which can lengthen or shorten by adding or subtracting individual actins) forming around the middle
199
why are microtubules important to the mitotic spindle
attach to sister chromatids during cell division; pull them apart and reform the nucleus
200
size progression of cytoskeleton components
(smallest) microfilaments --> intermediate filaments --> microtubules (largest)
201
what type of cell lines the small intestine
endothelial cells
202
what are microvillus
projections used to absorb nutrients, increases surface area for absorption from lumen of gut
203
what are cilia made of and why are they important
9 microtubules; important in airway which prevent particles from getting into lungs
204
what causes fluidity of lipid bilayer
movement of individual phospholipids
205
what are membrane proteins
Carry out most of specific functions
| Amount and types of proteins in a membrane are variable
206
3 classes of membrane proteins
integral, peripheral, and lipid-anchored proteins
207
integral proteins
(penetrate into the lipid bilayer) - most are transmembrane proteins (contain an alpha-helix of nonpolar amino acids extending across the hydrophobic interior of the membrane)
208
peripheral proteins
located outside of the lipid bilayer on the cytoplasmic surface attached by noncovalent bonds to the polar head groups of the lipid bilayer, or to integral membrane proteins
209
lipid-anchored proteins
covalently attached to a phospholipid or fatty acid embedded in the bilayer
210
Role of membrane proteins (3)
transport proteins
receptors for molecular messengers from other cells
form junctions between cells
211
what are MEMBRANE CARBOHYDRATES
Project from the exterior surface of the plasma membrane when attached to proteins or phospholipids within the membrane
Serve as recognition sites on the cell surface
212
what are glycoproteins
carbohydrates (oligosaccharides) in membranes bound to proteins that enable cells to recognize foreign substances
213
what are glycolipids
form cell identity markers eg. A,B, O blood group markers
214
types of cell junctions
tight junctions
desmosomes
gap junctions
215
why are gap junctions important in the heart
allow small molecules (e.g. iron) to move from cell to cell
| facilitates spread of action potentials (what tells the heart to beat)
216
what are plasmodesmata
aqueous pore in plant cells - analogous to gap junctions
217
what anchors extracellular matrix to exterior cytoskeleton and what is it attached to
integrin and attached noncovalently to fibronectin
218
what type of mechanism is an ion channel and how does it work
passive and nonmediated - creates an aqueos pore in the membrane
219
what type of mechanism is a carrier (transporter) and how does it work
passive and carrier mediated; carrier protein allows polar molecule to shuttle through
no aqueous pore is created
moves from high to low - facilitated by mechanism, but still passive because does not require to move against concentration gradient
220
what is diffusion
random molecular motion from areas of high concentration to lower concentration
221
what type of mechanism would move molecules against the concentration gradient
active, mediated transport involving a membrane protein carrier and requiring energy
222
what can diffuse across the lipid bilayer
Small nonpolar molecules, e.g. O2 and CO2
223
what is osmosis
Diffusion of water molecules across a selectively permeable membrane
224
why can't plant cells burst like animal cells can
stability from the cell wall
225
what is osmolarity
sum of ions in solution
226
benchmark osmolarity of blood plasma and hyposmotic and hyperosmotic
~300 mosmol/L
| 300
227
what regulates channel proteins
1. binding of some specific molecule (ligand gated)
| 2. change in voltage (voltage gated)
228
graphs of diffusion to see if it experiences saturation kinetics
1. linear would indicate it’s not carrier mediated and is 2. simple diffusion (does not experience saturation kinetics)
curved and eventually flattening out means it can saturate andyou will reach max rate of transport
229
uniport
molecule moves one direction
230
symport
molecules move same direction
231
antiport
molecules moving in opposite directions
232
what does Endocytosis do
transports macromolecules, large particles and small cells into eukaryotic cells
233
3 types of endocytosis
Phagocytosis, Pinocytosis, and Receptor-mediated endocytosis
234
what is phagocytosis
large particles or cells are engulfed
235
what is pinocytosis
small dissolved solutes or fluids enter
236
what is Receptor-mediated endocytosis
a specific membrane receptor binds to a particular macromolecule at sites called coated pits
237
what is endocytosis
taking molecules into cells
238
what is exocytosis
vesicle fusing and dumping outside
239
what is an exergonic reaction
A reaction whose products contain less free energy than the reactants (delta g is negative); tend to occur spontaneously and release heat; catabolism -- cell respiration
240
what is an an endergonic reaction
products of the reaction contain more energy than the reactants and the extra energy must be supplied for the reaction to occur; anabolism -- active transport and cell movements
241
what is the main carbohydrate store in humans
glycogen
242
what is the main lipid store in humans
triglycerides
243
what does metabolism do to energy stores
breaks it down into ATP
244
2 ways cells make atp
substrate-level phosphorylation
| chemiosmosis (most do this way)
245
how does substrate-level phophorylation work?
direct transfer of phosphate group to ADP from another molecule
246
why does breaking atp bonds release so much energy
it has negatively charged phosphates which are close to each other which takes a lot of energy, so breaking those binds releases lots of energy
247
is atp actually a nucleotide?
yes
248
how do autotrophs synthezise food molecules
using light energy
249
do heterotrophs or autotrophs extract energy from food?
trick! both do
250
stages of extracting energy from food
1. digestion - enzymes break large moleucles into smaller molecules
2. catabolism - other enzymes dismantle fragments extracting energy at each stage
251
what is harvested to generate ATP
Glucose (C6H12O6); C-H bonds; uses the energy from the electrons making up the bonds
252
what is glycolysis
conversion of glucose to pyruvate
253
what is cellular respiration
conversion of pyruvate to CO2 and water in the presence of O2 which releases large amounts of energy
254
where does chemiosmosis occur
mitochondria
255
where did the term oxydative phosphorylation come from?
experiment where mitochondria were put in a test tube with ADP and phosphate and oxygen and it makes ATP
256
what is the more current/accurate way to describe making ATP
chemiosmosis (in mitochondria)
257
which organelle can you use the terms chemiosmosis and substrate level phosphorylation intrchangeable and which ones can you not
mitochondria can use both, but chloroplasts cannot
258
how is atp generated by substrate-level phosphorylation
Involves direct transfer of phosphate group to ADP from another molecule
259
how is atp generated by chemiosmosis
glucose enters cells, converted to pyruvate, converted to CO2
260
what is NAD+
an electron shuttle; AN ELECTRON CARRIER IN MANY REDOX REACTIONS; Nicotinamide adenine dinucleotide
