Unit 1 - Biochemistry Flashcards
1
Q
What is hydrolysis?
A
The chemical reaction of adding H20 to a molecule, causing it to split in two
2
Q
What is a condensation/dehydration reaction?
A
The chemical reaction of removing an OH and H from a molecule in order to fuse the two
3
Q
What are the 6 functional groups?
A
- Hydroxyl
- Aldehyde
- Carbonyl
- Carboxyl
- Amino
- Ether
4
Q
What is the family and structure of Hydroxyl?
A
R-OH, Alcohols
5
Q
What is the family and structure of Aldehyde?
A
R-C=O,
l
H
Aldehydes. - CHO (at end)
6
Q
What is the family and structure of carbonyl?
A
.O
.l l
R - C - R,
Ketones. CO (in chain)
7
Q
What is the family and structure of carboxyl?
A
. R - C = O
. I
. OH
, Carboxylic acids. - COOH (at end)
8
Q
What is the structure and family of ether?
A
R-O-R, Ether. - O - (in chain)
8
Q
What is the structure and family of amino?
A
R - N - H
I
. H ,
Amines. - NH2 (at end)
9
Q
What’s an isomer?
A
An Isomer is a molecule with the same chemical formula as another but has a different structure
10
Q
What does Redox reaction stand for?
A
Reduction and oxidation
11
Q
What happens in a redox reaction?
A
Electrons are lost from one atom and gained by another atom
12
Q
What is reduction in a redox reaction?
A
A gain of electrons
12
Q
What is oxidation in a redox reaction?
A
A loss of electrons
13
Q
What chemicals are typically found in organic molecules?
A
C, H, O, and less often N, S
14
Q
What is an ionic bond?
A
A bond between two ions of opposite charge
14
Q
What is a covalent bond?
A
A bond created by atoms sharing one or more pairs of electrons.
15
Q
What is a polar bond?
A
A covalent bond in which one or more pairs of electrons is unequally shared (the molecule has a positive and negative end)
16
Q
What is a hydrogen bond?
A
A bond between a hydrogen atom and a highly electronegative atom (such as N, O, or F)
17
Q
What are the unique properties of water caused by hydrogen bonding?
A
- Surface tension
- Adhesion
- Ice is less dense than water
- High boiling point/vaporization point
18
Q
Why does water have surface tension?
A
Water molecules bond to each other
19
Q
Why does water climb up plant stems?
A
Water is attracted to other polar molecules
20
Q
Why does water have a high heat capacity?
A
Hydrogen bonding causes water to need to absorb much more heat before being able to transition to the next step on the heat ladder. Also causes water to lose heat quickly.
21
Q
Why is water less dense when its solid?
A
Frozen water forms an organized crystalline structure that liquid water doesnt have
22
What is a buffer?
A buffer is a solution that can resist pH change and is able to neutralize small amounts of added acid or base
23
How do buffers work?
conjugate acid and conjugate bases are both present in appreciable amounts at equilibrium and are able to neutralize small amounts of other acids and bases
24
What is the scale at which pH changes?
pH is a logarithmic scale. This means that for each one-digit change in pH, the acidity (H+ concentration) changes by 10 times.
25
What functional groups are in fats/lipids?
Hydroxyl, carboxyl, ester, alcohol family
26
What functional groups are in protein?
Amino, hydroxyl, carboxyl, phosphate, sulfhydryl
27
What functional groups are in carbohydrates?
Carbonyl, hydroxyl, ether
28
What are the main components of the cell?
- Plasma membrane
- Cell wall (plants only)
- Nucleus
- Endoplasmic reticulum and rough endoplasmic reticulum
- Ribosomes
- Golgi apparatus
- Vacuole (mostly plant)
- Lysozome
- Mitochondria
- Chloroplast (plants only)
- Cytoskeleton
- Cilia and flagella
- Centrioles
29
What does the plasma membrane do?
- Controls what enters and leaves the cell.
- The membrane is a double layer of water repellant molecules.
- Receptors in the outer surface detect signals to the cell and relay these to the interior.
- The membrane has pores that run from the cytoplasm to the surrounding fluid.
30
What is the cell wall?
- Plants only
- The cell wall supports plant tissue
- Composed of a fully permeable wall of cellulose
- Important structure in establishing turgidity
31
What is the nucleus?
- The nucleus has a double membrane with pores
- Nucleus controls the cell via expression of genes
- Some cells are multinucleated - ie muscles
32
What is the endoplasmic reticulum (ER)
- Synthesis of lipids, steroids, and carbs
- Metabolism of exogenous substances
33
What is the rough endoplasmic reticulum (rER)?
- Has ribosomes on its surface (giving rough appearance)
- Synthesizes proteins d packaging into vesicles.
- rER form a network of tubules with a maze like structure.
- In general these run away from the nucleus
- Proteins made here are secreted out of the cell
34
What is the golgi appartus?
- Modification of proteins for secretion
- possible addition of carbohydrate or lipid components to protein
- packaged into vesicles for secretion
35
What is a vacuole?
- The vacuole is a storage area in plants for amino acids and sugars (sap).
- The tonoplast is a membrane like the plasma membrane it controls what
enters and leaves the vacuole
36
What is the Lysozome?
- Vesicles that form on the golgi
apparatus.
- Containing hydrolytic enzymes.
- Functions include the digestion of old organelles, engulfed bacteria and viruses.
37
What is the mitochondria?
- Mitochondria is the site of aerobic respiration.
- The matrix is the site of the Krebs cycle
- Oxidative phosphorylation occurs on the cristae membrane
- Very active cells usually have a lot of mitochondria e.g. muscle cell
38
What is the chloroplast?
- In plants only this is the site of photosynthesis.
- Light is trapped by chlorophyll found on the thylakoids
- Carbohydrate is made using the trapped energy and carbon dioxide in the stroma
- Oxygen is produced as a waste gas from the process
39
What is the cytoskeleton?
- made up of microtubules, actin filaments, and intermediate filaments
- Give the cell its shape and help organize the cell's parts
- Provide a basis for movement and cell division
40
What are cilia and flagella?
- Cilia are hair-like organelle used to move substances along the outer surface of a cell
- Flagella are long, wavy structures that extend from the plasma membrane and are used to move an entire cell
41
What is the fluid mosaic model?
- The model of the cell membrane
- Fluid because phospholipids can change position
- Mosaic because of the embedded and attached protein molecules
42
What is the phospholipid bilayer and its function?
- Arranged in a bilayer, polar, phosphate heads out, non-polar, fatty acid tails in
- Acts as a barrier to all but O2 and CO2
- Can change position on the horizontal plane
43
What are integral proteins?
- In/on the phospholipid bilayer
- Usually involved in transporting proteins across the membrane
44
What are peripheral proteins?
- Sit on the surface of the phospholipid bilayer
- Can slide around quickly, hit each other, but will never flip to the other side
- Proteins on the inside of the bilayer are often involved in maintaining the cells shape or in cell mobility
-May also be enzymes, catalysing reactions in the cytoplasm
45
What are glycoproteins?
- Usually involved in cell recognition
- Can also act as receptors in cell signaling such as with hormones
46
What is cholesterol?
Bonds together lipid in the plasma membrane, reducing its fluidity
47
What are the bonds in proteins?
- Peptide bonds
- Hydrogen bonds
48
What are the bonds in lipids?
- Polar
- Non-polar
- Ester
49
What is a channel protein?
- Span the cell membrane from one side to the other
- Allow movement of large molecules across the cell membrane
- Includes passive and active membrane pumps
50
What are receptor proteins?
- Detect hormones arriving at cells to signal changes in function
- May also be involved in other cell and substance recognition
51
What are enzymes?
- Integral in the membrane for breaking things apart e.g ATP Synthetase, Maltase
52
What are electron carriers?
- Seen in photosynthesis and respiration in oxidation/reduction
- Common carriers are NADH and FAD
53
What is osmosis?
- the passive movement of water molecules across a partially permeable membrane from a region of lower solute concentration to a region of higher solute concentration
54
What is a hypertonic solution?
- Net movement of water is out of the cell
55
What is a hypotonic solution?
- Net movement of water is into the cell
56
What is an isotonic solution?
- Net movement is equal
57
What are different types of diffusion?
Lipid diffusion - Pass through the lipid bilayer with little resistance, e.g. oxygen, carbon dioxide, and water.
- Lipid molecules pass through easily too
Facilitated diffusion
- Larger molecules pass through using channels
- Channel proteins have large globular structures
- The channel shields the diffusing molecule from non-charged regions of the membrane
Active transport
- Active mean that the membrane protein 'pump' requires energy to function
- The source of energy is ATP from respiration
-This moves the molecules from low to
high concentration, against the concentration gradient
- The energy causes a shape change in the protein that allows it to move the molecule to the other side of the membrane.
58
What is membrane fusion?
The ability of the membrane to join together in a self sealing fashion has long been recorded in the processes of
* exocytosis
* endocytosis
* vesicle formation/fusion
This model shows endocytosis in which the engulfed particle is then digested by enzymes from the cell.
59
What is metabolism?
The sum of all the catabolic (degradative) and anabolic (synthetic) chemical reactions in the cell
60
What is the structure of ATP?
l. 3 Phosphate Groups
2. 5 C sugar [ribose)
3. nitrogenous base [adenine]
61
What is an exergonic reaction?
products contain less energy than the reactants and usable energy is released. e.g. respiration
62
What is an endergonic reaction?
products contain more energy than the reactants. Energy is required from an outside source. e.g. photosynthesis
63
What determines/affects enzyme activity?
- pH
- Reaction energy (effects speed)
- Catalyst (Lower the amount of reaction energy required, puts stress on bonds making them easier to break)
- Temperature
- Enzyme concentration
- Toxins
- Substrate concentration
64
What is a coenzyme?
organic substances that carry molecules from one enzyme to another
Ex. Vitamin derivatives (NAD+ or NADP+)
65
What is a cofactor?
inorganic substances that are needed for some enzymes to function
Ex. Dissolved ions
66
What is enzyme inhibition?
Competitive inhibitors
* Similar shape to substrate
* Can enter active site and block normal substrate from binding
* To reverse, increase substrate concentration
Noncompetitive inhibitors
* Attach to another site of the enzyme
* Cause change in enzyme shape
* Enzyme loses affinity for substrate
Ex. DDT inhibits enzymes of nervous system
67
What is allosteric regulation?
- Used to control enzyme activity (restrict production of enzymes or inhibit enzyme action)
- some enzymes posses allosteric sites (receptor sites)
- binding an activator to the allosteric site will stimulate enzyme activity (keeps active sites available)
- binding an inhibitor to the allosteric site will inhibit enzyme activity (it
stabilizes the inactive form of the enzyme)
68
What is feedback inhibition?
* Controls metabolic pathways involving a series of sequential reactions, each catalyzed by a specific enzyme
* Products formed in later steps will inhibit enzymes involved in earlier steps
* This reduces the production of the inhibitor
69
What is the model for enzyme activity?
Free enzyme + Free substrate, Enzyme-Substrate complex, Enzyme-Product Complex, Enzyme + Product
70
Toxin effects on enzyme activity:
Many toxic substances will break covalent bonds and cause the unraveling of the protein enzyme. Other toxic substances will precipitate enzymes effectively removing them from the solution thus preventing them from catalyzing the
reaction. This is also called denaturation.
71
The effect of temp on enzyme activity:
- Temp affects the kinetic energy for the reaction
- Too high temps may denature the enzyme/destabilize it
72
The effect of pH on enzyme activity:
- H+ (lower pH) interacts with active site (changing the shape)
73
The effect of substrate concentration on enzyme activity:
- More or less active sites to bind to
74
What is the neutralization of fatty acids?
Uses 3 hydroxyl ions
