6.1 Molecules of Living Systems Flashcards
1
Q
Organic Compounds
A
Living things are made up of them. They are also known as macromolecules. They always have carbon-hydrogen bonds.
2
Q
Carbon
A
- can form 4 covalent bonds due to 4 valence electrons
- polar and non-polar
- carbon chains form the skeleton(backbone) of most organic molecules
- carbon-carbon bonds are very strong
3
Q
Skeletons can vary in;
A
- length
- branching
- double-bond positions
- presence of rings
4
Q
Functional groups
A
They are chemical patterns/motifs that are added to hydrocarbons to give that macromolecule particular properties that allow it to have a certain functions
5
Q
The 7 types of functional groups
A
- Hydroxyl
- Sulfhydryl
- Methyl
- Carboxyl
- Carbonyl
- Amino
- Phosphate
6
Q
Hydroxyl Group
A
-OH
Polar
7
Q
Sulfhydryl group
A
-SH
Polar
8
Q
Methyl Group
A
-CH3
Non-polar
9
Q
Carboxyl Group
A
-COOH
Acidic
10
Q
Carbonyl Group
A
-CO
Polar
11
Q
Amino Group
A
-NH2
Basic
12
Q
Phosphate Group
A
-PO4
Acidic
13
Q
What is a Biomolecule(Macromolecule)
A
Bio= “life”
Molecule= group of molecules bonded together
Biomolecule is a chemical compound found in living organisms
14
Q
What essential elements are biomolecules made of
A
Carbon = Most Important
Hydrogen
Oxygen
Nitrogen
Phosphorus
Sulfur
15
Q
Monomer
A
small, single units that can bond to others to form large chains.
Created through Hydrolysis
16
Q
Polymer
A
larger molecules made of bonded monomers
Created though Dehydration Synthesis
17
Q
Hydrolysis
A
The chemical breakdown of a compound due to reaction with water
18
Q
Dehydration Synthesis
A
the creation of larger molecules from smaller monomers where a water molecule is released. (water is removed)
19
Q
What elements do carbohydrates contain?
A
Carbon
Oxygen
Hydrogen
20
Q
Monosaccharides
A
They are simple sugars. The most common of these is glucose. Other monosaccharides include fructose and galactose.
21
Q
Function of Carbohydrates
A
Carbohydrates are for energy release and storage in the body. Energy is important for movement and growth! Simple sugars like glucose can release energy quickly while other carbs have a slower release of energy.
22
Q
Monomers and Polymers
A
Monomers are single molecules that can link together to form polymers. Monosaccharides are the monomers of polysaccharides.
23
Q
Glucose, Galactose, Fructose
A
These monosaccharides have the same number of atoms but they are arranged in a different structure. They are called isomers of each other.
24
Q
Disaccharides
A
Form when two monosaccharides link/join together in a dehydration synthesis reaction. Different monosaccharides are used to build different disaccharides
25
Polysaccharides
They are long chains of monosaccharides linked together by glycosidic . They also form by dehydration synthesis.
26
Examples of polysaccharides
Amylopectin
Amylose
Cellulose
Glycogen
27
Amylopectin
A long branched chain - it's side branches let glucose get released quickly
28
Amylose
A long unbranched chain - it is coiled like a cylinder, making it compact and good for storage.
29
Cellulose
The long straight chains that can form hydrogen bond. This makes it good for providing support. eg. In the cell wall
30
Glycogen
A highly branched structure with many side branches. This allows for very quick release of glucose for animals. Very compact
31
What are Lipids?
They are a type of macromolecule that are insoluble in water. They are found in fats, oils, waxes, hormones and other important molecules
32
What are the components of fatty acids?
Consists of carboxyl group, hydrogen-carbon chain.
Elements of Carbon, Hydrogen, Oxygen
33
What are fatty acids?
They are a key component of many lipids. They consists of a carboxyl group joined to a hydrocarbon chain of variable length. They can be saturated or unsaturated
34
Saturated
No double bonds
C=C
35
Unsaturated
At least one double bond
C=C
36
Formation of triglycerides
Glycerol + 3 Fatty acids = Triglyceride + 3 Water molecules
Happens through dehydration synthesis
37
Function of triglycerides
Used in long term store for energy. they are stored in the body as fat which is good for insolation in cold habitats. They are good for storage as they are insoluble in water so they don't affect a cell's water potential
38
Hydrophobic
Water hating
39
Hydrophilic
Water loving
40
Function of phospholipids
They make up the cell/plasma membrane of cells. They form a bilayer, with the hydrophobic tails facing inwards and the hydrophilic heads facing outwards. Due to the polar nature of the tails, most water soluble molecules cannot pass through. In this way, the cell membrane controls what can enter and exit cell
41
Waxes
Very long chain of hydrocarbons. The are very water repellant and are solid at room temperature. plants use waxes in their leaves to prevent water loss. Some animals use waxes to clean and protect the ears. Bees use wax to build honey combs
42
Steroids
They have a basic structure of four rings of carbon atoms. They are still hydrophobic and insoluble in water.
43
Cholesterol
A type of steroid and is a key component of cell membranes. However, too much "bad" cholesterol can damage the body.
44
LDL Cholesterol
Low-density lipoprotein = BAD cholesterol.
High levels of LDL cholesterol causes fatty deposits to build up in the arteries, increasing the risk of heart disease and stroke. To reduce cholesterol, diets should be low in saturated fats & trans fats.
45
HDL Cholesterol
High-density lipoprotein = GOOD cholesterol.
46
Proteins
A type of macromolecule made from one or more chains of amino acids
Amino acids are the monomers of proteins
47
Key elements in proteins
Carbon
Hydrogen
Oxygen
Nitrogen
48
Dipeptides
Dipeptide are two amino acids joined together by a peptide bond
49
Polypeptides
Polypeptides are chains of many amino acids joined by peptide bonds
50
Essential amino acids
They cannot be made by the body. They must be obtained from food a person eats.
9 of 20 amino acids are essential amino acids
51
Primary Structure
Is it's polypeptide chain. This is a sequence of amino acids joined together by peptide bonds. This sequence is coded for by the genes(lengths of DNA) and it determines the proteins final 3D shape. The polypeptide is made through protein synthesis and varies in length from protein to protein
52
Secondary Structure
When a polypeptide chain gets folded, it can form alpha helices and beta pleated sheets. This folding is made possible by hydrogen-bonds between the carbonyl group of one amino acids and the amino group of another amino acid. In the alpha helix, the polypeptide chain is coiled into a ribbon-like structure. In the beta pleated sheets, the polypeptide chain folds into segments that line up beside each other
53
Tertiary Structure
The polypeptide gets folded into a 3D structure. Based mainly on the interactions of R-groups. Some hydrophobic and some Hydrophilic. Other bonds and interactions include disulfide bridges between nearby cysteines, ionic bonds
54
Quaternary Structure
When two or more polypeptide chains bond together. We call each polypeptide chain a subunit. The subunit are held together using the same types of bonds and interactions as are used in forming the tertiary structure
55
Functions of proteins
Proteins are incredibly diverse in their shaped due to the different levels of protein structure. Having different shapes lets them carry out different functions
56
Digestive enzymes
These help to break down food molecules in the digestive systems so that they can be absorbed in the small intestine
57
Contractile
Contractile proteins are incredibly important in animals as they allow them to move. They have special filaments that slide over each other
58
Transport
Some proteins help to move substances around the body in the blood stream or lymph
59
Defense
If harmful microorganisms, known as pathogens, enter the body, white blood cells produce defense proteins called antibodies. these can neutralize it or mark it for destruction by other cells
60
Hormones
These regulate many functions in the body by traveling in the blood to target organs
61
Structural
These proteins build different structures in cells such as the cytoskeleton
62
Storage
Some proteins provide a source of food for developing embryos in some animals
63
What are nucleic acids?
It is a type of macromolecules that carry important information. There are two types of nucleic acids: DNA, and RNA
64
The monomer of nucleic acids
Nucleotides
65
The two types of nucleic acids
DNA and RNA
66
Elements for nucleic acids
Carbon
Nitrogen
Oxygen
Hydrogen
Phosphorus
67
DNA
Deoxyribonucleic acid
Deoxyribose has a hydrogen atom at carbon 2
68
RNA
Ribonucleic acid
Ribose has a hydroxyl group of its carbon 2
69
Nitrogenous Bases and base pair rules in DNA
In DNA the nitrogenous bases are adenine, thymine, guanine, cytosine.
Adenine=Thymine
Guanine=Cytosine
70
Nitrogenous Bases and base pair rules in RNA
In RNA, thymine is replaced by uracil.
71
Purines
Bases with two rings
72
Pyrimidines
Bases with a single ring
A pyrimidine always pairs with a purine to give equal length "rungs" on the DNA "ladder"
73
Structure of DNA
- Double helix (2 strands)
- Anti-parallel
- Has base pairs
- It is a long molecule
74
Functions of DNA
- Contains genetic information
- Passed onto offspring
- Controls the cell's activities
75
Phosphodiester bonds
They are between adjacent nucleotides (sugar & phosphate)
76
Structure of RNA
- Usually single stranded
- Uracil instead of thymine
- It is shorter than DNA
- Broken down quickly
77
Functions of RNA
- Various functions
- Important in protein synthesis ( making proteins)
78
Types of RNA
tRNA = transfers RNA, carries amino acids
mRNA = messenger RNA, used to build proteins
rRNA = ribosomal RNA, makes up part of ribosomes
79
Location of DNA and RNA in the cell
DNA = found in the nucleus (there is also a small amount of DNA in the mitochondria - usually mothers)
RNA = found in both the nucleus and cytoplasm. prokaryotic calls have no nucleus
DNA and RNA are in the cytoplasm
80
What are enzymes
They are biological catalysts which means they can speed up reactions in the body without being used up themselves
They do this by lowering the activation energy of a reaction - this is how much energy is required for the reaction to start.
Most enzymes are proteins and have a specific shape due to their tertiary structure
81
Models of enzyme action
Originally, scientists thought that enzymes worked like a lock and key. the enzyme active site was perfectly complementary to the substrate
However, new evidence showed that the enzyme can change the shape of its active site as the substrate binds. This is called the induced fit model
82
pH environmental impacts on enzyme function
pH affects how well an enzyme functions. It is a measure of how acidic or basic/alkaline a substance is. Different enzymes have different optimal pH's (this is the pH at which it works best)
83
pH scale
0-6 = acidic
7 = neutral
8-14 = alkaline/basic
84
Denaturation
this happens when the pH is too far off the enzyme's optimal pH range. This disrupts the bonds that hold the enzyme together. This can change the shape of the active site which means the substrates that can no longer bind and the enzyme cannot catalyze the reaction
Denaturation is reversable and the enzyme can regain its functionality if the environmental conditions return within its optimal range. However sometimes change is permanent
85
Concentration
How much of a substance is in a specific area
86
Enzyme concentration
As the enzyme concentration increases, the rate of reaction increases and then plateaus. As the enzyme concentration increases, it results in more collisions with substrate, increasing the rate of reaction until all substrate molecules have bonded to active sites - ADDING MORE ENZYMES MAKES NO DIFFERENCE TO THE RATE OF REACTION
87
Substrate concentration
It has the same effect on the reaction rate as enzyme concentration
88
Cofactors and coenzymes
Some enzymes don't work at their optimum or at all without the help of other molecules known as cofactors. These can attach temporarily or permanently depending on the type of bond. Many COFACTORS are inorganic ions such as calcium or magnesium
89
Coenzymes
are a group of cofactors that are organic - this means they are carbon-based. We obtain many coenzymes from the vitamins that we eat in our diet
