Mock Exam Flashcards
2 factors which affect biodiversity
Deforestation reduces trees in a area in which animal use for shelter and food sources
Climate change melts icecaps Meaning polar bears don’t have their habitat
Name one feature of a mass transport system
All substances move in the same direction at the same speed
Why do large multicellular organisms have circulatory systems
Cannot obtain oxygen and nutrients or remove waste products through diffusion so require other means of transport
State two difference between arteries and veins
Veins have valves arteries don’t
Arteries small lumen. Veins large lumen
Name the 4 components of blood
Red blood cells
White blood cells
Platelets
Plasma
Name 3 substances transported in blood plasma
Oxygen
Carbon dioxide
Water
4 chambers of the heart
Left atrium right atrium
Left and right ventricle
State the function and importance of valves in the heart
Prevent back flow of blood which is important to prevent the mixing of oxygenated and deoxygenated blood
What are the 3 stages of the cardiac cycle
Diastole heart relaxes atria and ventricles fill with blood
Atrial systole atria contract forcing blood from the atria into the ventricles
Ventricular systole ventricles contract forcing blood from the ventricles to either the rest of the body of the lungs
What is active transport
Movement of molecules into or out of a cell from a region of lower concentration to a region of higher concentration against a concentration gradient.energy is needed provided by atp
What is osmosis
Diffusion of water across a partially permeable membrane passive no energy required
What is the function of channel proteins
Passive moving of polar molecules and ions down a concentration gradient through membranes
Describe the structure of the cell membrane
Arranged in a phospholipid bilayer
With hydrophilic head facing outwards and hydrophobic tails facing inwards
Presence of carrier and channel proteins which allow larger molecules to whether the membrane which can’t pass through diffusion
How are disaccharides formed
Two monosaccharides OH groups are close together and react forming a glycosidic bond between the two molecules
One one similarity and difference between amylose and amylopectin
Amylose is linear amylopectin is branched
Amylose has 1-4 glycocydic bonds amylopectin has 1-4 1-6 glycocyduc bonds
Both polysaccharides
Both used in energy storage
Why is water important for the body
Acts as a transport median for molecules to be transported
Acts as a coolant which helps preserve enzyme activity and prevent denaturing this is due to large amounts of energy required to break hydrogen bonds so a constant temperature is maintained
Name 3 treatments for heart disease
Antihypertensives reduce blood pressure
Statins reduce blood cholesterol levels
Anticoagulants reduce formation of blood clots
What makes up the primary structure of a protein
Sequence of amino acids held together by peptide bonds
What’s are start and stop codons
Start codon is the site where protein translation initiates
Stop codon marks the termination of the translation progress
What is the function of tRNA
Form of RNA which helps transport amino acids.
What are the 3 parts of a nucleotide
Sugar
Phosphate group
Base
State 3 ways exchange surfaces are adapted for efficient exchange
Large surface area-provides large area needed for exchange and overcomes limitations of SA TO V ratio in larger organisms
Short diffusion distance-distance substances have to move is shorter so the process is fast and efficient
Good blood supply-steeper the concentration the quicker diffusion takes place