Topic 2 Flashcards
(82 cards)
1
Q
What happens when an organism inc in size
A
- Volume increases
- Greater size of organ, lowe SA:V
2
Q
What are Exchange Surfaces adapted for
A
-efficiency of gas and solute exchange across them
3
Q
Thin Membrane adaptation for Gas Ex
A
-reduces diffusion distance
4
Q
Large Surface Area adaptation for Gas Ex
A
-Allows a greater amount of substance to diffuse at the same time
5
Q
Blood Vessels adaptation for Gas Ex
A
- In animals, substances are exchanged through blood
- exchange surfaces densely packed to replenish blood supply
6
Q
Exchange surfaces adaptation for Gas Ex.
A
-maximise the efficiency of gas and solute
7
Q
Ficks Law
A
-Rate of Diffusion = (SA x Conc diff)/thickness of surface
8
Q
Diffusion rate in Ficks Law
A
-DR is higher when SA and Diff C are larger, thickness of Surface is smaller
9
Q
What aids Active Transport?
A
-Carrier Proteins - Facilitates movement
10
Q
Example of Active Transport?
A
- Sugar Absorption in the gut
- allows sugar molecules (respiration) to be absorbed into blood via gut
- even when sugar conc. in blood higher
11
Q
Two Main factors of Active Transport?
A
- SA of cell membranes
- Number of carrier proteins in cell membranes
12
Q
What is Active Transport?
A
- Molecules move from a less conc. solution too higher conc. solution against a concentration gradient
- Energy via respiration
13
Q
What type of structure is an enzyme determined from
A
-tertiary
14
Q
What is the Enzyme Active Site?
A
- Only catalyses one specific reaction
- Complementary to the specific substrate
15
Q
Environmental factors that determine the specificity of the enzyme?
A
- 3D tertiary structure
- Polyp. chain determines Active site
16
Q
How do enzymes catalyse reactions?
A
-Lowering the activation energy
17
Q
Activation Energy?
A
-Amount of energy needed for the reaction to take place
18
Q
Lock and Key Hypothesis
A
-Proposes that enzyme and substrate fit together perfectly
19
Q
Induced fit Theory?
A
-More dynamic interaction
20
Q
Bronchioles
A
-Millions of small branches throughout lungs
21
Q
Alveoli
A
-Sacs that fill with air when breath in
22
Q
Bronchi
A
-Air flows along the lungs
23
Q
Trachea
A
-Entrance to gas exchange system
24
Q
3 things Ventilation is controlled by
A
- Bones that form the ribcage
- Diaphragm
- Intercostal Muscles
25
Capillaries role in gas exchange
- Surrounds Alveolis
| - Provide a large surface area
26
Alveolar Epithelium
- Single Layer
- Provide very short diffusion distance
- Maximises gas exchange rate
27
Concentration Gradient at the Alveoli
- Capillaries provide Co2, ,Oxygen at Alveoli
| - Steep concentration gradient
28
What does the Permeability of the Cell Membrane depend on
- Solvent Concentration
- pH
- Temperature
29
What are Phospholipids made out of
- Glycerol
- Two Fatty Acids
- Phosphate
30
Where is cholesterol in the membrane
- Core of the Membrane
| - Maintains shape of animal cells
31
Solvent Concentration effect on Phospholipid Bilayer and how can it be controlled?
- More easily dissolved = More Permeable membrane
| - Can be Controlled if using same Solvent for each trial
32
pH effect on Phospholipid Bilayer and how can it be controlled?
- pH affects protein structure
| - Buffer solutions can control this
33
Temperature effect on Phospholipid Bilayer and how can it be controlled?
- Higher temp increases fluidity of bilayer
| - using a water bath
34
First Step of Cell Membrane Beetroot Practical
-Collect Beetroot Sample
35
Second Step of Cell Membrane Beetroot Practical
-Place samples in Ethanol for 10 minutes
36
Third Step of Cell Membrane Beetroot Practical
-Remove discs from solutions
37
Fourth Step of Cell Membrane Beetroot Practical
-Calibrate the Colorimeter
38
Fifth Step of Cell Membrane Beetroot Practical
-Measure the absorbance of each solution
39
5 Steps of Cell Membrane Beetroot Practical
1) Collect Beetroot Sample
2) Place samples in Ethanol for 10 minutes
3) Remove discs from solutions
4) Calibrate the Colorimeter
5) Measure the absorbance of each solution
40
Plasma Membrane
-Structure that defines the border of cells
41
Glycoproteins and Glycolipids function
-signalling receptors
42
Osmosis
-Diffusion of water across a partially permeable membrane from a low concentration solution to a high concentration solution
43
Partial Permeable Membrane
-Allows water through, not larger molecules
44
Primary Structure of Proteins
-Dependent on structure of Amino Acids
45
Amino Acid Sequence
-Specific sequence to determine Primary Structure
46
Importance of a change in amino acid sequence
- Could lead to change in amino acid being produced
| - Could change structure and function
47
Secondary Structure of Proteins
-Polypeptide chain folding
48
Hydrogen bonds in Polypeptide chain determining Secondary Structure?
- Amino Acids can form hydrogen bonds between eachother
| - These cause chain to fold which determines secondary structure
49
Common Features of Secondary Structure
-Alpha Helix and Beta Pleated Sheets
50
Stability in Secondary Structure
- High Number of bonds leads to stability
| - Can be affected via environmental factors - pH, Temp
51
Tertiary Structure
- Secondary structure folds even more
| - Creates Three Dimensional shape
52
R groups effect on Tertiary Structure
- Side chains on amino acids
| - Interactions between R groups lead to 3D structure
53
Quaternary Structure
-3D polypeptides come together to form this structure
54
Examples of Quaternary structure
- Haemoglobin
| - Insulin
55
Haemoglobin Quaternary structure features
-four polypeptides surrounding central Haem group
56
Insulin Quaternary structure features
-Combination of Hydrogen bonds and Disulfide bridges
57
What is Exocytosis and Endocytosis responsible for?
-Ways in which substances can be actively transported across membranes using ATP
58
Endocytosis?
- Cell engulfs a substance from its surroundings
| - Fluid cell membrane folds around substance
59
Exocytosis?
- Membrane-bound vesicles fuse with plasma membranes before releasing into surroundings
- used when cells produce a substance which needs to be exported
60
Transcription?
mRNA produced in the nucleus
61
Transcription steps?
1) Binding of RNA Polymerase
2) Separation of DNA strands
3) Binding to template strands
4) Joining the Nucleotides
5) STOP codon
6) Removal of mRNA
7) mRNA leaves Nucleus
62
Transcription - (1)Binding of RNA Polymerase
- This enzyme allows transcription to take place
| - Binds to Locus of gene
63
Transcription - (2)Separation of DNA strands
- When RNA Poly. binds to DNA
| - Triggers Hydrogen bonds so DNA unwinds (exposes bases)
64
Transcription - (3)Binding to Template strands
- RNA Poly. binds free floating RNA nucleotides to template strands
- This forms mRNA - complementary to the gene
65
Transcription - (4)Joining the Nucleotides
-Phosphodiester bonds formed in between nucleotides
66
Transcription - (5)STOP Codon
-RNA Poly. reaches stop codon 'UAG'
67
Transcription -(6)Removal of mRNA
-mRNA strand separated from template by RNA Poly.
68
Transcription -(7)mRNA leaves nucleus
-mRNA leaves nucleus and enters cytoplasm
69
Translation steps?
1) Attachment to Ribosome
2) Binding of tRNA
3) Bringing in Amino Acids
4) Binding of Second tRNA
5) Movement of the Ribosome
6) STOP Codon
7) Completion of Polypeptide
70
Translation -(1)Attachment to Ribosome
-mRNA binds to Ribosome (sight of Protein Synthesis)
71
Translation -(2)Binding of tRNA
- One Molecule of tRNA binds to first codon in ribosome
| - tRNA has anticodon complementary to specific codon
72
Translation -(3)Bringing in Amino Acids
-Each tRNA molecule carries a specific amino acid to the ribosome
73
Translation -(4)Binding of Second tRNA
- tRNA binds to second codon in ribosome
- tRNA binds to mRNA, corresponding amino acid is brought to ribosome
- Peptide bond formed between amino acids
74
Translation -(5)Movement of the Ribosome
- When amino acid is formed
| - Ribosome moves along mRNA strand so new codon enters ribosome
75
Translation -(6)STOP Codon
-Ribosome reaches UAG then stops
76
Translation -(7)Completion of Polypeptide
-Polypeptide chain formed
77
How does DNA Replication Occur
- each of two DNA strands used as template
| - New strands copied
78
What is DNA made up of
-Two Polynucleotide strands that form a double helix
79
Why is DNA known to be Semi-conservative
- After Replication DNA is made up of one polynucleotide strand
- One original strand is conserved
80
3 steps of DNA Replication
1) DNA helicase binds to DNA and breaks hydrogen bonds between strands (strands separate)
2) Free-floating Nucleotides form hydrogen bonds with complementary bases
3) DNA polymerase forms Phosphodiester bonds between nucleotides
81
What is DNA Polymerase responsible for?
- Catalyses condensation reaction between nucleotides in DNA strand
- forms phosphodiester bonds between adjacent nucleotides
82
Watson and Crick's discovery of DNA replication
- Specific base pairing involved in copying sequences of genetic information
- thought each strand = template which complementary strand copied
- Did not know how replication took place
