Bio Exam Flashcards
1
Q
What are the four main types of macromolecules?
A
Carbohydrates, Proteins, Nucleic Acids, Lipids
2
Q
What is the simplest form of carbohydrates?
A
Monosaccharides
3
Q
What are important polysaccharides and their functions?
A
- Glycogen: energy storage, highly branched
- Starch: energy storage in plants (Amylose is unbranched, Amylopectin is branched)
- Cellulose: structural support in plants
- Chitin: structural support in exoskeletons and fungi
4
Q
What is the ratio of carbon, hydrogen, and oxygen in carbohydrates?
A
1:2:1
5
Q
What functional groups are present in carbohydrates?
A
Carbonyl and hydroxyl
6
Q
What types of linkages bond simple sugars in carbohydrates?
A
Glycosidic linkages
7
Q
Fill in the blank: The first OH of alpha glucose is pointed ______.
A
DOWN
8
Q
Fill in the blank: The first OH of beta glucose is pointed ______.
A
UP
9
Q
What major roles do lipids serve?
A
- Energy storage
- Insulation
- Hormonal functions
10
Q
What is the structure of triglycerides?
A
1 glycerol and 3 fatty acid chains
11
Q
Difference between saturated and unsaturated fats?
A
- Saturated: straight chain, tightly packed
- Unsaturated: double bonds cause bending
12
Q
What are the four groups of lipids?
A
- Triglycerides
- Phospholipids
- Steroids
- Waxes
13
Q
What is the primary role of proteins?
A
- Structural support
- Catalyzing reactions
- Transport
- Communication
14
Q
What are the levels of protein structure?
A
- Primary: linear sequence of amino acids
- Secondary: hydrogen bonding between amino acids
- Tertiary: folding due to interactions
- Quaternary: multiple polypeptides join
15
Q
What are the three components of a nucleotide?
A
- Sugar with 5 carbon atoms
- Phosphate group
- Nitrogen-containing base
16
Q
What distinguishes DNA from RNA?
A
- DNA: deoxyribose, A T G C, double-stranded, in the nucleus
- RNA: ribose, A U G C, single-stranded, found everywhere
17
Q
What is the role of enzymes in biological reactions?
A
They lower the activation energy, speeding up reactions
18
Q
What is activation energy?
A
The amount of energy needed to begin a chemical reaction
19
Q
Fill in the blank: Substrate is the ______ that an enzyme acts on.
A
reactant
20
Q
What is the induced fit model?
A
The enzyme changes shape slightly to fit the substrate upon binding
21
Q
Factors affecting enzyme activity include:
A
- Temperature
- pH
- Substrate concentration
22
Q
What are cofactors and coenzymes?
A
- Cofactors: often inorganic metals that improve substrate fit
- Coenzymes: organic cofactors derived from vitamins
23
Q
What are competitive and non-competitive inhibitors?
A
- Competitive: block the active site
- Non-competitive: bind to allosteric site, altering enzyme shape
24
Q
What factors affect membrane fluidity?
A
- Presence of double bonds
- Length of fatty acid tails
- Temperature
- Presence of cholesterol
25
What are the two types of membrane proteins?
* Peripheral: on inner/outer surface
* Integral: span the entire membrane
26
Define passive transport.
Transport that does not require energy, moving down the concentration gradient
27
What is facilitated diffusion?
Transport assisted by proteins for molecules that cannot pass through the membrane unassisted
28
What is active transport?
Transport of a solute against its concentration gradient, requiring energy
29
What are the types of endocytosis?
* Phagocytosis: cellular eating
* Pinocytosis: cellular drinking
* Receptor-mediated: receptor proteins bind to molecules and form vesicles
30
What happens in a hypotonic solution for animal and plant cells?
* Animal: water enters, may burst (lysis)
* Plant: central vacuole fills, turgor pressure increases
31
What is the primary goal of aerobic respiration?
To break down glucose into carbon dioxide and water while trapping energy in ATP
32
What is the structure of DNA?
Double stranded molecule consisting of nucleotides with antiparallel strands
33
What are the three phases of DNA replication?
* Initiation
* Elongation
* Termination
34
What is the role of helicase in DNA replication?
Unwinds and unzips the parent DNA
35
What is PCR?
A method for amplifying large amounts of DNA from small quantities
36
What is gel electrophoresis used for?
Separation of DNA fragments by size
37
What is a point mutation?
A change in a single nucleotide in the DNA sequence
38
What is a silent mutation?
A change in DNA sequence that does not affect the amino acid sequence of the protein
39
What are the four possible nucleotides incorporated in DNA?
Adenine, Thymine, Cytosine, Guanine
40
What is a silent mutation?
A change in the DNA sequence where the amino acid sequence of the protein remains unchanged
41
What is a substitution mutation?
One nucleotide is replaced by another in the DNA sequence
42
What is a transition mutation?
A point mutation where a purine is substituted for another purine or a pyrimidine for another pyrimidine
43
What is a transversion mutation?
A point mutation where a purine is replaced by a pyrimidine or vice versa
44
What is an inversion mutation?
A section of DNA is reversed or flipped
45
What is an insertion mutation?
The addition of one or more nucleotides in DNA
46
What is a deletion mutation?
The removal of one or more nucleotides in DNA
47
What is a frameshift mutation?
A mutation that alters the reading frame, resulting in a nonfunctional protein
48
What is a non-frameshift mutation?
A mutation where the number of nucleotides inserted or deleted is a multiple of 3
49
What is a nonsense mutation?
A mutation that codes for a stop codon
50
What is a missense mutation?
A mutation that replaces one amino acid with another
51
What is a conservative missense mutation?
A mutation where one amino acid is replaced by another with similar properties
52
What is a non-conservative missense mutation?
A mutation where one amino acid is replaced by another with different chemical properties
53
What is homeostasis?
The maintenance of a stable internal environment
54
What is hydrogen bonding?
A strong dipole-dipole attractive force between a hydrogen atom covalently bonded to a highly electronegative atom and a highly electronegative atom of a different molecule
55
What is the structure of a hydroxyl functional group?
–OH
56
What type of compounds do hydroxyl groups form?
Alcohols
57
What is the structure of a carbonyl group in ketones?
C=O within the skeleton
58
What is the structure of a carbonyl group in aldehydes?
C=O at the end of the skeleton
59
What is the structure of a carboxyl functional group?
–COOH
60
What type of compounds do carboxyl groups form?
Carboxylic acids or organic acids
61
What is the structure of an amino functional group?
–NH2
62
What type of compounds do phosphate groups form?
Organic phosphates
63
What are the steps of cellular respiration?
1. Glycolysis- cytoplasm, anaerobic
- glucose goes in
- 2 atp used
- 2 pyruvate made
- 2 atp made for each pyruvate (4 in total)
- 2 NADH made for later
Glucose-->2 pyruvate + 2ATP(x2) + 2 NADH
2. Pyruvate Oxidation
- pyruvate transported into mitochondria (matrix)
- pyruvate is oxidized
- 2 pyruvate converted to 2 acetyl-CoA + 2NADH, CO2 is released
2 Pyruvate-->2 acetyl-CoA + 2NADH
3. Krebs Cycle
- still in mitochondrial matrix
- 2 rounds of this
- produces: (1 ATP, 3 NADH, 1FADH2, 1 Acetyl Co-A, 2CO2) x2
2 acetyl-CoA --> 2ATP + 6NADH + 2FADH2; 4CO2 released
4. Electron Transport Chain
- inside inner mitochondrial membrane
- 6NADH and 2FADH2 enter ETC
6NADH- 2FADH2--> release elections in ETC--> 32-34 ATP's produced
- oxygen final electron acceptor
64
What is the net ATP produced from glycolysis?
2 ATP
65
Where does pyruvate oxidation occur?
Mitochondrial matrix
66
What is produced in the Krebs Cycle?
1 ATP, 3 NADH, 1 FADH2 per cycle
67
What is the final electron acceptor in the electron transport chain?
Oxygen
68
What is the overall equation for photosynthesis?
6 CO2 + 6 H2O + radiant energy → C6H12O6 + 6 O2
69
What are the two main stages of photosynthesis?
Light reactions and light-independent reactions (Calvin cycle)
70
What occurs during the light reactions of photosynthesis?
Photon energy is absorbed, water is split, and ATP and NADPH are produced
71
What is the main product of the Calvin Cycle?
Carbohydrates
72
What is the role of rubisco in the Calvin Cycle?
Catalyzes the reaction of CO₂ with ribulose 1,5-bisphosphate (RuBP)
73
What factors affect the rate of photosynthesis?
Light intensity, temperature, CO2 concentration, O2 concentration, color of light, genetics
74
What is the resting membrane potential of a neuron?
-70mV
75
What triggers an action potential?
When the threshold potential is reached at -50mV
76
What is the role of neurotransmitters?
Carry nerve impulses across the synapse
77
What is an excitatory neurotransmitter?
A neurotransmitter that increases the likelihood of an action potential
78
What is an inhibitory neurotransmitter?
A neurotransmitter that decreases the likelihood of an action potential
79
Structures of the nervous sytsem
Central Nervous system
- Brain
- Spinal cord
Peripheral Nervous system
- Sensory pathways
- Motor pathways
Motor pathways
- Somatic nervous system (under conscious control- voluntary)
- Autonomic nervous system (not under conscious control- involuntary)
Autonomic nervous system
- Sympathetic nervous system
- Parasympathetic nervous system
80
Summary of the ETC
FNN H+ H+ O
The function of the electron transport chain is to use energy temporarily stored in NADH and FADH2 to produce ATP
NADH (from pyruvate oxidation) is oxidized by NADH dehydrogenase (NADH donates h+ and 2 electrons). The energy of the electrons is used to pump H+ ions into the intermembrane space (the space between the inner and outer mitochondrial membrane)
Next, electrons get passed down the ETC, pumping H+ ions into the intermembrane space at 2 more locations (3 in total).
The H+ ions accumulate in the intermembrane space, creating an electro-chemical gradient.
Ions are only able to re-enter the matrix through the ATP synthase channel. Their energy is used to produce energy from ADP and Pi. (Chemiosmosis)
Oxygen is the female electron acceptor, it reacts with the electrons and hydrogen ions at the end to create water. (oxygen picks up electrons from the cytochrome oxidase, which is the last pump in the ETC.
Total number of ATP produced per glucose:
2 NADH from glycolysis (2 from each G3P) x2 ATP each =4ATP
2 FADH2 (1 from each G3P) x2 ATP each =4 ATP
8 NADH (from pyruvate oxidation and Krebs cycle) x2 ATP (2 rounds)= 2 ATP
81
What is the total ATP formed from cellular respiration?
TOTAL ATP = 2 from glycolysis, 2 from kreb’s cycle, 32-34 from ETC
= total 36-38 ATP (36 in eukaryotic and 38 in prokaryotic)
Overall reaction: glucose + oxygen → carbon dioxide + water + ATP
82
Action vs Resting potential
Resting- the electrical charge difference across the membrane when the cell is not actively sending a signal -70mv
- the cell is preparing for the possibility of action potential
Action- a rapid, temporary change in the electrical charge across the membrane when a cell is activated to send a signal
- this allows communication within the nervous system
