Biology unfamiliar terms - Flashcards
(130 cards)
1
Q
Genetic code -
A
A triplet code, which is non-overlapping, degenerate and universal
2
Q
Codon -
A
Contains 3 bases and coded for an amino acid
3
Q
Triplet code -
A
Sequences of bases along the chain of nucleotides made up of 2 strands of DNA, sequence of 3 bases called a codon. Coding for an amino acid.
4
Q
Gene -
A
A section of DNA that contains the complete sequences of bases (Codons) for an entire protein.
5
Q
Non-overlapping (Genetic code) -
A
Each base triplet (codon) is read in a sequence, separate from the triplet before it and after it. So base triplets don’t share bases and is non-overlapping.
6
Q
Degenerate (Genetic code) -
A
There are more codons than amino acids, therefore many amino acids can be coded for than one or more codons.
7
Q
Universal (Genetic code) -
A
All organisms use the same code, although the coding for each sequences of bases for an individual protein will be different.
8
Q
mRNA -
A
- Made in the nucleus during transcription
- Carries the genetic code of DNA to the cytoplasm where it makes a protein during translation.
- Contain codons
9
Q
tRNA -
A
- Found in the cytoplasm
- Has an amino acid binding site at one end and a sequence of 3 bases called the anticodons
- Carries the amino acids that are used to make proteins to the ribosomes.
10
Q
rRNA -
A
- Forms the 2 subunits on a ribosome (small and large)
- Ribosome move along the mRNA strand during translation
- Main job of rRNA allows the catalyse of peptide bonds between amino acids.
11
Q
Amino acid structure -
A
H R
N - C - COOH
H H
12
Q
Peptidal transferase (Enzyme) -
A
Catalyses reactions of many enzymes joined back to back (Site of protein synthesis)
13
Q
Homologous chromosomes -
A
Each nucleus of the organisms contains 2 full sets of genes, pair of genes for each characteristic, each nucleus contains matching sets of chromosomes. One full set from mother and the other farther. In diploid organisms. Sister chromatids
14
Q
Independent assortment -
A
Where the orientation of each homologous pair on the metaphase plate is random and can end up facing either pole. Happens in metaphase I and II. Leads to diverse allele combinations.
15
Q
Crossing over -
A
Exchange of genetic material of the homologous pairs of chromosomes, occurs during meiosis 1 prophase , occurs due to the chromatids entangling when they are brought together of non-sister chromatids.
16
Q
Open circulatory systems contain what transport medium and the large body cavity where it is stored is called? (Invertebrates)
A
Haemolymph (Medium after exchanging with tissues and cells returns to the heart through open ended vessels and doesn’t carry oxygen or carbon dioxide).
Haemocoel
17
Q
Single circulatory systems pass through how many sets of capillaries before returning to the heart?
A
2
1. Exchanges co2 and o2
2. substances are exchanged between blood and cells
Blood returns to the heart slowly under less pressure.
Double = 1 set of capillaries
18
Q
Affinity for oxygen means -
A
How strongly oxygen and haemoglobin binds (2 molecules)
19
Q
Elastic fibres function -
A
Contain elastin used for stretch and recoil offering flexibility for blood vessels
20
Q
Smooth muscle function -
A
Alters the size of the lumen contracting or relaxing.
21
Q
Collagen function -
A
Structural support of the vessel
22
Q
% of blood is different due to the amount of plasma and blood cells their are?
A
45% of blood is WBC’S and RBC’S
55% is plasma
23
Q
What is plasma?
A
Makes up 55% of blood and carries RBC’s and WBC’s, is a yellow liquid and carries other useful substances of glucose and AA and hormones
24
Q
Platlets - (mega …. )
A
Large cells - Megakaryocytes formed in the red bone marrow
25
Tissue fluid is?
- Fluid surrounding cells
- Made from substances that leave the blood plasma through the capillary walls to be exchanged.
- Don't contain larger substances as there too large to be forced out.
- Affects or affected by hydrostatic and oncotic pressure
26
Hydrostatic pressure -
(Hydro = water)
Blood is still under pressure from being travelled through the arterioles (surges) into the capillaries.
Pressure in relatively higher than oncotic pressure of water moving back into the capillary
27
Oncotic pressure -
Hydrostatic pressure reduced in the capillaries so water potential decreases due to the larger plasma proteins that remain behind. Water potential is higher in the tissue fluid than the capillaries so water moves back through the venule end by oncotic pressure
28
Lymph -
Some of the tissue fluid does not return to the capillaries at the venule end, returns through the lymphatic system. Moves back through to the heart back lymph capillaries, gradually moves back to the heart in the thorax.
29
Partial pressure (pO2) and what the amount of saturation does for a haemoglobin molecule -
Measure of oxygen concentration in a mixture of gases. Change of saturation results in a change of shape of haemoglobin meaning oxygen molecules may be added more rapidly.
30
Gill filaments -
- Large stacks, need a flow of water to keep them apart exposing the larger S.A needed for gaseous exchange.
31
Bohr shift -
- As proportion of co2 increases the oxygen dissociation curve for haemoglobin moves right as more oxygen is released from the blood, due to he partial pressure of carbon dioxide, haemoglobin gives up oxygen much easier.
32
Dissociation curve shows?
- How saturated the haemoglobin is with o2
100% = each haemoglobin is carrying 4 oxygen molecules (o2)
33
Gill lamellae -
- Main site of gaseous exchange from their rich blood supply and large surface area.
34
Homeostasis -
Maintaining of dynamic equilibrium, with small fluctuations over a narrow range of conditions. Relying on receptors and effectors and feedback systems. (Regulation of water balance or internal temperature)
35
Cell signalling -
Cell communication where multicellular organisms can coordinate functions and respond to their environments internally or externally.
36
Thermoregulation meaning -
Where animals can internally regulate their own body temperature (hypothalamus) and is in both endotherms and ectotherms.
37
As partial pressure of co2 rises?
Haemoglobin gives up oxygen more easily (Bohr effect)
38
What do the hepatic vein and artery do for the liver?
V - removal of deoxygenated blood from the liver
A - Supplies oxygenated blood to the liver
39
Hepatic portal vein -
Carries blood loaded with products ready for digestion from the duodenum and the ileum (small intestine) up to 75% is from here. Carries to the liver
40
Liver cells are what and what organelles do they contain?
Hepatocytes, (large nuclei, golgi apparatus and mitochondria). Makes liver a regenerating tissue.
41
Sinusoids -
Spaces which mix the blood from hepatic vein and artery, surrounded by hepatocyte. (Leads to Central vein).
42
Kupffer cells -
Attached to the walls of the sinusoids. Macrophages breaking down invading pathogens and break down of blood.
43
Secretion of bile in liver -
From hepatocytes from the breakdown of blood into spaces called the bile canaliculi, these lead to bile ducts to the gall bladder.
44
Function of hepatocyte (Transamination) -
Conversion of one amino acid to another, important in diet to contain the right balance of AA.
45
Deamination from a hepatocyte 1 - why and the product formed where does it go>
Excess proteins need to be excreted and cannot be stored. They remove the amine group and convert it into ammonia (NH3) which is toxic and forced to turn into urea and is excreted by the kidneys.
46
Ornithine cycle (where and how) -
Bunch of enzyme controlled reaction which turn a highly toxic substance of ammonia into urea. Happens where in the mitochondria of hepatocytes where NH3 combines with CO2.
47
Detoxification of toxins in the liver -
Toxins can increase from elsewhere, other than ammonia. Drugs and alcohol contain toxins, Detoxification can take these and make them less harmful through enzymes.
48
Alcohol detoxification -
Alcohol contain ethanol which is a toxin, hepatocytes contain alcohol dehydrogenase which breaks it down into ethanal, which can be used in building up fatty acids or cellular respiration.
49
Hydrogen peroxide detoxification -
Enzyme catalase in hepatocytes can take hydrogen peroxide which is made in cellular respiration and form it into less harmful products of oxygen and water.
50
Cardiac output is measure d in what?
L/per M (Litres per minute)
51
What is stroke volume measured in?
Litres or more more commonly millimetres per beat
52
Bohr effect occurs in which two regions (high o2 rate)
Lungs and active tissues
L - CO2 is lower in partial pressure, so haemoglobin gives up oxygen much more easily
AT- lower binding if CO2 allows successful binding of oxygen
Both lower affinity to hemp oxygen binding in haemoglobin
53
Transport of co2 is carried in the red blood cells -
54
CO2 reacts with water to form what?
Carbonic acid. Dissociates to form hydrogen carbonate ions and hydrogen ions
55
Carbonic anhydrase speeds up the reaction between
CO2 and H2O
56
Transport of CO2 from tissues results in Hydrogen carbonate ions moving where down a electrochemical gradient and chloride ions moving where to maintain an electrical balance called what?
1. Out the erythrocyte
2. In the erythrocyte
3. Chloride shift
Is a reversible process so when reaching the lungs, opposite happens
57
Cardiac cycle is myogenic meaning -
It has its own intrinsic rhythm, where the rhythm begins at the Sino-arterial node (Pacemaker)
58
SAN -
- Where the wave of electrical excitation occurs (begins heartbeat)
- Non-conducting tissue stops the excitement of ventricles contacting (AVN job)
59
AVN -
Picks up the excitement of the SAN, and slightly delays before stimulating the bundle of his where the purkyne fibres penetrate through the septum.
Bundle of his splits into two branches activating the contraction of the ventricles
60
Bradycardia heartbeat -
(B tier)
Usually people who are fit where the heartbeat is slower (artificial pacemaker counters this)
61
Tachycardia heartbeat -
(Turbo)
Where the heartbeat is rapid (may be due to fitness)
62
Ectopic heartbeat -
(Extra)
Extra heartbeats out of rhythm
63
Arterial fibrillation of heartbeat -
(Abnormal)
Abnormal rhythm of heartbeat
64
Source to sink in phloem meaning -
Sources - origin of where made
Sink - tissues and cells that need them
65
Important cell types of mature phloem are - (which 2 types)
Sieve tubes and companion cells
66
Sieve tubes -
- End of walls contain sieve plates for assimilates to move up and down a plant.
- Organelles break down because of this
- Main transporting vessels
67
Companion cells -
- Closely linked to sieve tube elements through plasmodesmata (close channels through cellulose cell wall)
- Life support system due to lack of organelles
68
Water travels across through the roots via -
Root cortex, low W.P in the root due to solutes so osmosis occurs
69
Symplast pathway -
Neighbouring cells of plasmodesmata of living cells allow it to move through, concentration gradient is maintained through roots and outside roots as W.P falls again allowing osmosis again.
Not blocked by endodermis.
70
Apoplast pathway - (endodermis)
- Moves through open spaces of the cellulose membrane and pull through due to cohesive forces.
Endodermis - blocks transport of water along with casparian strip in the pathway so it joins the symplast pathway.
71
What causes water to move up the vascular bundle once inside the xylem?
Root pressure along with the xylem having little mineral or solutes so water can move down a concentration gradient.
72
Transpiration stream -
Moves water from roots and beginning of vascular bundle to the leaves, water leaves as water vapour from going up the apoplast pathway. The water evaporate from mesophyll cells and move into external spaces where they leave out the stomata which is regulated by guard cell which is used to regulate gaseous exchange, transpiration is inevitable. Water moving up in a continuous stream is transpiration pull.
73
Adhesion + cohesion =
Cohesion tension theory - resulting in capillary action so they can rise up against a narrow tube against the force of gravity.
74
Turgor pressure -
Hydrostatic pressure that occurs within a cell causing strain on the plasma membrane
75
Humidity affecting water transpiration -
Humidity is the amount of water vapour in the air where high humidity will decrease transpiration because it will reduce the water potential gradient inside making it unlikely for water to leave to another high conc.
76
Translocation (source examples) -
Green leaves and stems due to the occurrence of photosynthesis. Main assimilate transported is sucrose.
77
Translocation (sink) -
Meristems - where cells are actively dividing
Roots - which are growing
78
Order of potency (H-L) -
Totipotent
Pluripotent
Multipotent
79
Assimilates are loaded two ways in the phloem from being made by the source -
Symplast and apoplast route
s - mesophyll cells, ends up in sieve tubes with water following, moving through the plasmodesmata. Mass flow is achieved by water
a - cell walls, concentration is maintained by removal of sucrose.
80
Sucrose is moved into the cytoplasm of sieve tubes from companion cells from an active process. Sucrose moves into the cell by what process and H+ is a what?
Active transport and co-transport protein
81
H+ as a co-transporter protein and its role in phloem loading of sucrose -
1. Actively pumped out of the CC from ATP
2. So more outside in the surrounding tissue
3. Sucrose in the outside is co -transported and binds to the protein at the same time
4. Sucrose move into the sieve tubes by moving through the plasmodesmata
82
Final stage of glycolysis is dehydrogenation along with the formation of ATP (SLP) -
1. The triose bisphosphates are oxidised and hydrogen is removed (Dehydrogenation)
2. NAD coenzymes become reduces with the hydrogen
3. 4 ATP molecules are made from the use of the phosphate groups on the triose bisphosphate
An example of substrate-level phosphorylation as ATP is made without the intervention of a ETC.
5. Forms 2 pyruvates
83
The link reaction can be known as?
Oxidative carboxylation
84
Link reaction basic steps of the beginning oxidative decarboxylation -
1. Occurs in the mitochondrial matrix
2. Pyruvate undergoes oxidative decarboxylation
3. So it loses a carbon molecule of the 3 that pyruvate contain
4. A hydrogen molecule is oxidised and forms a reduced NAD
85
Link reaction formation of the 2 carbon molecule -
1. Forms a acetyl group from Oxidative decarboxylation
2. Reacts with coenzyme A
3. = Acetyl CoA
4. An acetyl group is delivered to the krebs cycle by the acetyl CoA
4. The acetyl group is all that is left of the original glucose molecule
86
Briefing of the krebs cycle (Non steps just summary) -
- Occurs in the mitochondrial matrix
- Each complete cycle results in the break down of one acetyl group
- FAD coenzyme is now involved
87
Krebs cycle first 3 steps -
1. Acetyl group brought by links reaction by Acetyl CoA
2. Where the 2 carbon molecule combines with a 4 carbon molecule oxaloacetate to from citrate
3. The citrate molecule (6C) undergoes decarboxylation and dehydrogenation twice forming a 4 then 4 carbon molecule which returns to become oxaloacetate. Causing the cycle to continue .
88
Products of krebs cycle -
More carbon dioxide and 2 more reduced NAD'S and 1 Reduced FAD. ATP is produced by substrate-level phosphorylation.
89
The need for coenzymes in respiration -
Coenzymes transfer protons, electrons along with functional groups, they are involved in a series of redox reactions where transferring protons and electrons would not allow many respiratory enzymes to function.
90
Differences between NAD and FAD -
NAD is in all stages of respiration whereas FAD is only accepts hydrogen in the krebs cycle.
NAD accepts one hydrogen where FAD accepts two.
Reduced NAD is oxidised at the start of the ETC where reduced FAD is oxidised further down the chain.
Both are coenzymes and derived from vitamins.
91
Oxidative phosphorylation takes place where?
Cristae of the mitochondria
92
FAD and NAD that collect hydrogen atoms deliver them to the ETC where the hydrogen atoms do what?
Dissociate into electrons and hydrogen ions, the energy of the electrons is used in the synthesis of ATP by chemiosmosis.
93
Energy is released during redox reactions -
Electrons oxidise and reduce as they flow along the ETC, creates a proton gradient leading to the diffusion of protons through ATP resulting in the synthesis of ATP.
94
Role of the final electron acceptor -
At the end of the ETC electrons combine with hydrogen ions and oxygen to form water, so oxygen is the final electron acceptor and it cannot operate without oxygen making it an aerobic process.
95
Why does NADH synthesise more ATP than FADH -
NADH donates its electrons to the electron transport chain earlier, at Complex I, while FADH2 donates its electrons at Complex II
96
How do the electrons move down the ETC?
Electron carries pump protons into the intermembrane space from the mitochondrial matrix forming an electrochemical gradient back into the matrix via ATP synthase where it synthesises ADP and Pi to form ATP.
97
Chemiosmosis in oxidative phosphorylation is achieved how?
Production of ATP is driven by the net movement of electrons over and down a transport chain down an electron chemical gradient is made resulting in the production of ATP.
98
How much ATP is made from NADH?
2.5 ATP
99
How much ATP is made from FAD?
1.5 ATP
100
Substrate - level phosphorylation -
Involves the production of ATP involving the transfer of a phosphate group from a short-lived highly intermediate like creatine phosphate. Does not involve oxidative phosphorylation (which is REDOX reactions)
101
Organisms that cannot survive in oxygen?
Obligate anaerobes all are prokaryotic basically.
102
Two types of Anaerobic respiration -
Alcoholic fermentation and lactate fermentation.
103
Fermentation -
Process of which complex organic compounds are broken down simpler inorganic compounds without the use of ETC so oxygen, the small quantity of ATP is produced is from substrate-level phosphorylation alone.
104
Lactate fermentation in mammals -
Reduced NAD is oxidised onto Pyruvate to make lactate or lactic acid (lactate dehydrogenase). Regenerates NAD meaning so a small amount of ATP can be produced. Too much lactate causes causes pH change and is toxic so is removed from the bloodstream and converts it back into glucose from gluconeogenesis.
105
Alcoholic fermentation occurs in yeast cells -
C02 is removed from pyruvate, where NADH oxidises and gives ethanal hydrogen forming ethanol, NAD can be reused in glycolysis.
106
ATP yield is less in anaerobic compared to aerobic -
Because anaerobic has only one energy releasing stage of glycolysis producing a net yield of 2 ATP where aerobic has multiple energy releasing stage which all work together to finally produce much more ATP (E.G net 32 ATP can be made in oxidative phosphorylation)
107
Respiratory quotient can be measure by ?
Volume of CO2 produced divided by Volume of 02 produced.
108
Different respiratory substrates have different energy values how?
Because most ATP is made in oxidative phosphorylation, which requires hydrogen atoms from reduced NAD to give electron and hydrogen ions in electrochemical gradient. Lipids contain the most out of hydrogen so more ATP is produced where they respire.
109
Photosynthesis equation =
6C02 + 6H20 = 602 + C6 H12 06 (Glucose)
110
Thylakoids -
Flattened membrane sacs increasing S.A which are fluid filled to make a grana/granum
111
Chlorophyll -
Absorb light found in the thylakoid membranes
112
Stroma -
Infused fluid
113
Thylakoids -
Link the grana of the stacks of thylakoids together.
114
The two photosystems in photosynthesis -
PS1 and PS2
PS1 - Light dependent
PS2 -Light independent
115
Light dependent stage -
- Energy is used from sunlight making the form of ATP (ADP to ATP)
- Takes place in the Thylakoids
- Water is used to reduce coenzymes NADP
116
Light independent reaction -
Hydrogen from reduced NADP and CO2 is used to build organic molecules such as glucose, takes place in the stroma and calvin cycle happens.
117
Light dependent stage where sunlight is absorbed is used for three things?
1. Formation of ADP to ATP with the use of an organic phosphate
2. Making NADPH from NADP
3. Splitting of water into protons (H+) electrons and hydrogen (photolysis)
118
Light dependent and light independent are cyclic or non-cyclic?
L = Cyclic - the electrons leaving the PS1 after the ETC can also be reused instead of NADPH - cyclic phosphorylation back to PS1
NL = Non cyclic
119
Light excites electrons in the chlorophyll -
Excitation in photosystem 2 results high energy electrons moving along the to PS1. ATP is made by chemiosmosis.
120
Photolysis in PSII -
Due to the electrons previously excited from the chlorophyll they leave the PSII and move down the ETC. Photolysis basically replaces the electrons lost by the splitting of water to make oxygen and hydrogen ions (protons)
121
PSII AND PSI wavelength -
2 = 680nm
1 = 700nm
122
How do the excited electrons move from the thylakoid to the stroma -
Energy results in the pumping of the transport protons, so that thylakoid has a high conc of them, they move down a proton gradient down an enzyme ATP synthase. The energy combines the reaction of ADP +pi = ATP. (Chemiosmosis)
123
Electrons at the end of Light-dependent reaction of PS1 oxidises on?
NADP becoming reduced NADP
124
Both photosystems are non - cyclic but which photosystem is cyclic?
PS1 (It doesn't always but can be involved in both)
125
Calvin cycle in the light independent reaction is also known as CO2 fixation?
AS CO2 fixes on organic molecules
126
First stage of Calvin cycle -
- CO2 enters the stroma through the stomata
- It combines with a 5 carbon molecule known as ribulose bisphosphate (RuBP) - catalyses the reaction of the two by rubsisco an enzyme
- The carbon dioxide is fixed on the molecule and breaks into 2 molecules due to being unstable
- Makes 2 3 - carbon molecule glycerate 3 phosphate
127
Second stage of calvin cycle (What happens to GP) -
- Converted in triose phosphate
- Achieved from the products of the Light dependent reaction (ATP + H+)
- Reduced NADP oxidises on the molecules of GP making them TP
- TP is converted into many useful compounds
128
Regeneration of ribulose bisphosphate in the calvin cycle -
It is recycled from triose phosphate, most of the molecules of TP aren't used to make hexose sugars but the regeneration of RuBP.
129
How many times does the calvin cycle need to turn to make a hexose molecule?
6 times
3 turns produce 6 triose phosphate and 5 of these molecules are used to regenerate RuBP. meaning they get one triose phosphate out of it, 6 turns makes 2 TP = 6 carbon molecules (hexose molecule)
130
Where does the secretion of the bile in the liver of the hepatocytes take place?
Bile canalicul
