Water 2.2
Lipids and Carbs
2.3
2.3
Proteins and Enzymes 2.4 and 2.5
DNA, RNA and Protein Synthesis 2.6 and 2.7
Cellular Respiration and Photosynthesis 2.8 and 2.9
100
What does it mean for water to be polar?
Water has a partial negative charge at one end (O) and a partial positive at the other (H).
100
Which biomolecule has the following molecular ratios
1Carbon:2Hydrogens:1Oxygen
carbohydrates
100
What type of biomolecule are enzymes?
100
What does it mean for DNA to be antiparallel?
The two strands go in opposite directions.
100
What is the equation for aerobic cellular respiration?
200
What is a hydrogen bond?
The weak bonds between polar molecules
200
Give an example of one monosaccharaide and one polysaccharide.
200
Describe the function of enzymes using the term reaction, substrate, active site and product.
Enzymes are proteins that increase the rate of a chemical reaction. Substrates bind into the active site, creating an ideal environment for the formation of the product.
200
Compare DNA and RNA structure [3 marks]
200
Describe the function of ATP
ATP is a short-term energy storage molecule
Energy is released when a phosphate is broken off
300
Describe how water is used as a coolant.
The evaporation of water requires energy from the surface of the skin. Because water has a high specific heat capacity, it absorbs a lot of thermal energy before it evaporates, cooling the skin
300
Identify two examples of lipids and their functions.
phospholipid - cell membrane
triglyceride - store energy
wax - waterproofing
cholesterol - membrane fluidity
300
What happens to proteins when they are in environments with very different pH or temperature?
Denaturation - losing of protein shape (and function) due to changes in hydrogen bonds and charges
300
Put these steps of protein synthesis in the correct order:
1. mRNA travels to the ribosome (rRNA)
2. DNA is read to create mRNA by following the base-pairing rules
3. Amino acids are attached to the growing polypeptide chain.
4. Anticodons of tRNA bind to codons mRNA
1. DNA is read to create mRNA by following the base-pairing rules
2. mRNA travels to the ribosome (rRNA)
3. Anticodons of tRNA bind to codons mRNA
4. Amino acids are attached to the growing polypeptide chain.
300
What are the products and uses of anerobic respiration by yeast?
ethanol - alcohol
CO2 - rising bread
400
Water is considered the universal solvent. Name 2 things that can dissolve well in water.
Anything hydrophilic.
- Sodium chloride (NaCl) is freely transported within the blood
- Oxygen is soluble in water but in low amounts – most oxygen is transported by haemoglobin within red blood cells
- Glucose contains many hydroxyl groups (–OH) which may associate with water and thus can freely travel within the blood
- Amino acids will be transported in the blood in an ionized state
400
When three fatty acids and a glycerol are joined together in a condensation reaction, what are the products?
400
Draw a generalized dipeptide.
400
List the components of polymerase chain reaction (PCR).
Taq polymerase - a heat-stable DNA ploymerase
RNA primers - bind to the correct sequence of DNA to initiate replication
DNA nucleotides - to form the new strands
Thermocycler - machine that uses variation in temperature to :1. denature DNA (90C) 2. Anneal primers (55C) 3. Elongate strands (75C)
400
What is the role of chlorophyll?
Absorbs red and blue light and reflects green light in the chloroplast. The energy absorbed is used for photosynthesis.
500
Why does water have a much higher boiling point than methane?
- Water is polar and can form intermolecular hydrogen bonds (due to high electronegativity of oxygen atom)
- Methane is non-polar and can only form weak dispersion forces between its molecules (carbon has a lower electronegativity)
500
Describe the health effects of cis, trans and saturated fatty acids.
500
Describe the process of the production of lactose free milk.
Lactase breaks lactose into glucose and galactose, which people with lactose intolerance can digest.
500
Translate the RNA sequence: AUG ACG AAU GGG UAA
Met Thr Asn Gly STOP
500
Describe the effect of changing CO2 concentration on photosynthesis.
