Biochemistry, atoms and molecules of life Flashcards
1
Q
List the 6 characteristics of life
A
- Organisms consist of cells
- Organisms grow and develop
- Organisms regulate their own metabolic processes
- Organisms react to stimuli
- Organisms reproduce
- Organisms and populations adapt to their environment
2
Q
List the biological organisation
A
Atom; Molecule; Organelles; Cell; Tissue; Organ; Organ system; Organism; Population; Community; Ecosystem
3
Q
Give the definition for an atom
A
The smallest unit of matter (living/non living) that can take part in a chemical reaction
4
Q
Give the definition for a molecule
A
Two or more atoms that combine with each other chemically
5
Q
Give the definition of elements
A
Pure substance that cannot be broken down into simpler substances through chemical means
6
Q
Give the definition of compounds
A
Pure substance that is made up of simpler substances (elements), in other words two or more elements that are chemically combined
7
Q
Give the definition of organelles
A
Subcellular structure that has one or more specific job to perform in the cell
8
Q
Give the definition of cells
A
The smallest unit of life that contains cellular inclusions (organelles)
9
Q
Give the definition of tissue
A
A group of similarly differentiated cells that perform a common function
10
Q
Give the definition of organs
A
A group of different tissues, each which perform their own functions, but together perform a common function
11
Q
Give the definition for an organ system
A
A group of organs that work together to perform a certain function in an organisms body
12
Q
Give the definition for an organism
A
A living thing that has an organised structure, can react to stimuli, reproduce, grow, adapt and maintain homeostasis
13
Q
Give the definition of a population
A
A group of organisms of the same species that live together
14
Q
Give the definition for a community
A
All the populations of different organisms and different species that live together
15
Q
Give the definition of an ecosystem
A
A particular area in which living (biotic) components interact with each other and with non living (abiotic) components.
16
Q
Give the definition of biomes
A
Any area with a particular climate, together with all the living organisms occurring in that area. There are terrestrial (land) and aquatic (water) biomes
17
Q
What are the properties of inorganic compounds
A
- Do not have a living origin
- Do not contain the element carbon. The exceptions are carbon dioxide (CO2), carbon monoxide (CO), cyanide compounds (-CN) and the carbonates (-CO3) that contain carbon but don’t have carbon-hydrogen bonds.
- Are elements and simple molecules
- Do not burn in oxygen
18
Q
What are the properties of organic compounds
A
- Have their origin in living organisms
- Contain the element carbon. Examples are carbohydrates, lipids, proteins, nucleic acids and vitamins which form the building blocks of cells
- Usually large and complex molecules
- Combustible in oxygen
19
Q
What are the functions of water in living organisms
A
- Solvent
- Medium in which chemical reactions occur
- Reagent during hydrolysis
- Transporting agent
- Lubricant
- Regulates body temperature
- Gives shape and rigidity
20
Q
Explain what hydrostatic skeletons are
A
Fluid filled bodies that give shape and rigidity to animals such as earthworms or jellyfish
21
Q
What is turgor pressure
A
Internal pressure caused by water in the vacuoles of plants cell that pushes against the cell wall
22
Q
What is the difference between a hydrophilic and hydrophobic substance
A
Hydrophilic substances readily react with water and have an affinity for it, maximising contact.
Hydrophobic substances do not dissolve in water and naturally repel it causing droplets to form
23
Q
What are minerals
A
Inorganic substances/ elements that are needed and absorbed by living organisms.
24
Q
List the different macronutrients and micronutrients and explain the difference
A
Macronutrients are minerals needed in large quantities every day such as C,H,O,N,P,S, Ca, Mg
Micronutrients are less required such as Fe, Na and Iodine
25
What is hydrolysis
When water breaks polymers down into their monomers
26
What is the difference between perspiration and transpiration
Perspiration is when sweat glands in humans produce sweat which cools the body as it evaporates from the body surface.
Transpiration is when plants are cooled by the loss of water vapour from their leaves.
27
Which vitamins are fat soluble
Vitamin A.D,E and K
28
Which vitamins are water soluble
Vitamin B and C
29
What is the pH of blood
7.4
30
What happens if blood is too acidic or too alkaline
Too acidic blood can lead to coma or death. Alkaline blood leads to nervous problems and convulsions
31
What is homeostasis
The need for humans to maintain a constant internal environment in the body to function optimally
32
What is a buffer
A chemical substance that counteracts pH changes by binding with or releasing excess H ions
33
What do electrolytes do
Electrolytes can conduct electric currents and play an important role in conducting nerve impulses as well as muscle functioning
34
Name the main organic compounds
Carbohydrates, lipids, proteins and nucleic acid
35
What is the difference between a monomer and a polymer
Monomers are the small sub units that bond to form a polymer
36
What elements make up carbohydrates
C, H, O
37
In what ratio are the elements in carbohydrates bonded
C: H : O
1: 2: 1
38
What are the types of saccharides
Monosaccharides, Disaccharides, Polysaccharides
39
How many carbon atoms are in a monosaccharide
3-7
40
Are monosaccharides soluble in water
Yes
41
What are the types of monosaccharides and give examples of each
1. Triose sugars, an example is glyceraldehyde
2. Pentose sugars, examples are ribose (RNA) and deoxyribose (DNA)
3. Hexose sugars, examples are glucose, fructose and galactose
42
What is the basic building block of all carbohydrates
Glucose
43
What organic compounds is glucose used to form part of
Amino acids and fatty acids
44
What hormones are blood sugar levels (Glucose) controlled by
Insulin and glucagon
45
Which is sweeter between glucose and fructose
Fructose
46
What does galactose form part of
Lactose, milk sugar
47
When does a disaccharide occur and what is the result
They occur when two monosaccharides are joined. One water molecule is removed to form a disaccharide. A condensation reaction occurs as a result and glycosidic bonds form
48
List 3 Disaccharides and what they consist of
1. Sucrose, consists of glucose and fructose
2. Lactose, consists of galactose and glucose
3. Maltose, consist of 2 glucose monosaccharides
49
Name where malt sugar is found
Germinating seeds of grain
50
What are polysaccharides
Long chains of monosaccharides that bind to one another by a condensation reaction
51
List the types of polysaccharides and where they are found/stored
1. Starch, stored in plants
2. Glycogen, stored in animals as reverse energy source usually in muscle and liver cells
3. Cellulose, it is a structural connection in the cell walls of plants
4. Chitin, found in the exoskeleton of insects as well as the cell walls of fungi
52
What is the difference between amylase and amylopectin
Amylase has shorter, unbranched chains of monosaccharides and is soluble to a certain degree.
Amylopectin has long, unbranched chains consisting of 1000 glucose molecules and is not soluble in water
53
Between glycogen and cellulose which is soluble in water
Glycogen
54
Why do we need cellulose in our diet
To help with peristalsis
55
What is the importance of carbohydrates in plants and animals
1. Source of energy
2. Source of reserve energy
3. Structural component
56
What are lipids soluble in
Non polar solvents such as ether
57
What elements are lipids made up of
C, H, O
58
What are triglycerides
Compounds formed when 3 molecules of fatty acids bind to one molecule of glycerol
59
What is glycerol
A type of alcohol with 3 hydroxyl group
60
What kind of chains do fatty acids have
Long hydrocarbon chains
61
Where are saturated and unsaturated fats found, give examples and what state are they at room temperature
Saturated fats are found from animals eg. butter/lard. They are solid at room temperature
Unsaturated fats are found from plants eg. olive oil/sunflower oil. They are liquids at room temperature
62
In what ratio are hydrogen and oxygen bonded in lipids compared to in carbohydrates
The H:O ratio in lipids is much higher than it is in carbohydrates
63
What are saturated fats used for in the body
They are used by the body to synthesize cholesterol
64
What is cholesterol and what does it form
It is a white, wax like substance that forms part of the cell membranes and hormones
65
What is atherosclerosis and how does high cholesterol levels lead to health problems
Atherosclerosis is when high cholesterol levels in the blood cause fatty deposits (plaque) in the arteries and narrowing them. Blood platelets aggregate at these narrow areas and form a blood clot, this can lead to angina or heart attack
66
Why are lipids important
1. Source of reserve energy
2. Insulating material
3. Structural component of cell membranes
4. Shock absorption
5. Waterproofing
6. Absorption of minerals
7. Source of water
67
What elements do proteins consist of
C,H,O,N and may be bound to other elements such as Fe, P and S
68
What are proteins made up of
Amino acids
69
How many amino acids are in a protein
51+ amino acids linked by peptide bonds
70
How many common amino acids are there (from which all proteins in living organisms are made)
20
71
How many of the common amino acids are essential and why are they essential
9, They are essential because they can't be synthesized in the body from other compounds and must be obtained from the diet
72
Fill in the missing words:
| Amino acids are bonded together by _______ to form _____
Amino acids are bonded together by PEPTIDE BONDS to form PEPTIDES
73
Describe the primary structure of a protein
Refers to a sequence of amino acids joined together by peptide bonds to form a polypeptide chain
74
Describe the secondary structure of a protein
First level of 3D folding. Its driven by hydrogen bonding. Results in the chain coiling and other regions forming sheets
75
Describe the tertiary structure of a protein
Second level of 3D folding. The chain folds into globular shape driven by hydrophobic interactions and electrostatic attractions
76
Describe the quaternary structure of a protein
The complete structures associate together by hydrophobic and electrostatic interactions to form the final protein.
77
What is the importance of proteins
1. Structural component of protoplasm
2. Building material
3. Structural component of cell membranes
4. Source of reserve energy
5. Hormones regulate processes in the body
6. Haemoglobin transports oxygen and carbon dioxide in the blood
7. Protects the body against disease
8. Chromosomes carry hereditary material
9. Act as buffers
10. Enzymes control metabolic processes in the body
78
What is an enzyme
A biological catalyst that accelerates a chemical reaction by lowering the activation energy, without itself being changed by the reaction
79
Explain the difference between catabolic and anabolic reactions
During catabolic reactions a complex molecule is broken down into simpler molecules and energy is released.
During anabolic reactions a complex molecule is built up from simple molecules and energy is required
80
What is an active site
The region where the substrate fits into the enzyme for the chemical reaction to occur
81
What does it mean when we say enzymes are substrate specific
A specific enzyme can only act of a specific substrate
82
What is a substrate
The substance on which an enzyme acts
83
Explain what occurs when an enzyme acts on a substance
The substance which the enzyme acts on is called a substrate. The substance formed during the reaction is the product. The substrate molecule fits into the the enzymes active site. (enzymes are substrate specific)
The enzyme lowers the activation energy of the reaction. The substrate changes chemically and leaves the active site. The enzyme remains unchanged
84
What is the difference between a co enzyme, co factor and apo enzyme
Apo enzymes are enzymes that need non protein portions (co factors) to perform their functions. Co enzymes are the organic non protein portions that bind to apo enzymes and act as co factors.
85
Do vitamins or minerals act as co enzymes
vitamins
86
What is co enzyme A's role
It is important for respiration
87
At what temperature do enzymes function best in humans
37 degrees celcius
88
What happens when proteins (enzymes) denture
The hydrogen hydrophobic and electrostatic interactions that result in the proteins 3D shape break down and unravel the protein into its primary structure, a long chain of amino acids. The shape of the active site and the shape of the protein is altered. The substrate can no longer fit and chemical reactions cant happen.
89
What does a low temperature do to enzymes
It can slow down or inactivate enzymes because of the low kinetic energy
90
What is affected when an enzyme is exposed to a pH outside of its range
pH affects the charge on some amino acids so the electrostatic interactions holding the tertiary structure together are affected
91
What are the factors that affect enzyme action
Temperature and pH
92
What elements do nucleic acids consist of
C, H, O, N, P
93
What are the types of nucleic acids
DNA (deoxyribonucleic acid)
| RNA (ribonucleic acid)
94
Where is DNA found and what does form part of
It is found the nucleus of the cell and forms part of the chromatin network and chromosomes (during cell division)
95
What are the functions of DNA
It carries hereditary characteristics and controls the structure and function of the cell
96
Where is RNA found and what does it form part of
It is found in the nucleus and cytoplasm of cells and forms part of ribosomes
97
What is the function of RNA
It plays a role in protein synthesis to ensure that the amino acids bind to one another in a certain sequence according to the instructions provided by the DNA
98
Why are vitamins essential
They are essential for normal metabolism, growth and development of the human body
99
Where are water soluble vitamins stored
They are not stored in the body and are excreted in urine so they must be taken regularly
100
Where are fat soluble vitamins stored
They are stored in the body
101
What do we use to test for glucose
Benedict's solution
102
What do we use to test for starch
Iodine solution
103
What do we use to test for lipids
Ethanol/ Ether
104
What do we use to test for proteins
Biuret test
105
What is the definition for eutrophication
The process by which a body of water becomes enriched in dissolved nutrients (such as phosphates) that stimulate the growth of aquatic plant life usually resulting in the depletion of dissolved oxygen.
106
What is hypoxia and dead zone
Hypoxia: Low in oxygen
| Dead Zone: Devoid of oxygen and animal life
107
Explain eutrophication
Excessive nutrients enter waterways from fertilisers. nutrients help develop plant growth and algal blooms occur. algae dies and is decomposed by bacteria. decomposition of algae increases biological oxygen demand. fish and other aquatic life forms die.
