Biology - paper 1 Flashcards
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How long does the cell cycle take?
Anywhere from 24 hours to years (depending on organism)
What is mitosis?
Process of cell division, resulting in two identical cells
What is stage 1 of the cell cycle?
- Longest stage
- grows bigger
- increased mass
- duplicate their DNA
- increase number of ribosomes, mitochondria etc for cell divide
What is stage 2 of the cell cycle?
-mitosis occurs
- organelles get pulled apart and nucleus splits
What is stage 3 of the cell cycle?
- cytoplasm and cell membrane split
- two identical daughter cells
What is therapeutic cloning?
Research using cells from an adult to produce a cloned embryo of themselves.
What could stem cells cure?
- spinal cord injuries
- diabetes
- eyesight
- heart damage
- damaged bone and cartilage
What do enzymes do?
Break down large molecules for digestion to occur
What does the liver do?
Produces bile
What are the main compounds of a cell?
Carbohydrates, lipids and proteins
What are simple carbohydrates?
Compsed of only one or two units of sugars
What are complex carbohydrates?
Composed of long chains of simple sugar units bonded
What are proteins made of?
Carbon, oxygen, nitrogen and hyrdogen
What is the definition of denatured?
Loss of an enzyme’s normal shape so that it no longer functions
What causes something to become denatured
If the pH or temperature is too low / too high
What is a catalyst?
A substance that speeds up the rate of a chemical reaction
What is an enzyme?
Proteins that act as a biological catalyst
What is enzyme activity affected by?
Temperature and pH
What are temperatures affects on enzyme activity?
Higher temps denature the enzyme and change the shape of the active site
What are pH affects on enzyme activity?
Interefers with the forces between proteins, therefore the shape changes and can no longer act on that site.
Where is amylase produced?
Mouth and small intestine
Where is protease produced?
Stomach, pancreas, small intestine
Where is lipase produced?
Pancreas and small intestine
What is pepsine?
Protein digesting enzyme
Where is bile produced?
Liver
Where is bile stored?
Gallbladder
How are red blood cells adapted to their functions?
- no nucleus
- packed with haemoglobin
- biconcave disks
What are arteries?
Blood vessels that carry blood away from the heart
What are veins?
Blood vessels that carry blood back to the heart.
What are capillaries?
Any of the fine branching blood vessels that form a network between the arterioles and venules
What are coronary arteries?
Blood vessels that branch from the aorta and carry oxygen-rich blood to the heart
What is the atria?
Two upper chambers of the heart
What is vena cava?
Large vein carrying deoxygenated blood into the heart
What are pulmonary veins?
Deliver oxygen rich blood from lungs to left atrium
what are the ventricles?
Two lower chambers of the heart
What is the pulmonary artery?
Artery carrying oxygen-poor blood from heart to the lungs
What is the aorta?
The large arterial trunk that carries blood from the heart to be distributed by branch arteries through the body
What is coronary heart disease?
Clogging of vessels that nourish heart, treated with stent or bypass and often prescribed statins
What is a stent?
Wire-mesh tube used to keep arteries open
What are statins?
Drugs used to lower cholesterol in the bloodstream
What is a mechanical valve?
Man made valve but must be on medication for life - made from titanium
What is a biological valve?
Last 12-15 years, no medication
- made using pig valves
What is the resting heart rate?
7-80BPM
What is an artificial heart?
A pump designed to fit into human chest cavity and perform the heart’s function
What are alveoli?
Air sacs in the lungs
What are alveoli adaptions?
- thin walls make diffusion easy as there is a short diffusion distance
- spherical shape of the alveoli gives large surface area for diffusion
What does the phloem tissue do?
Transports glucose and other dissolved sugars from the leaves to other parts of the plants
What is translocation?
The movement of dissolved sugars from the leaves to the rest of the plant
What does the xylem tissue do?
Moves water and dissolved minerals from the roots up the stem to the leaves where these substances are used in photosynthesis
What is transpiration?
Evaporation of water from the leaves of a plant
What factors affect the rate of photosynthesis?
Light intensity
Temperature
Air flow
Humidity
How do pathogens cause disease?
1 - bacteria multiply and produce toxins that lead to illness
2 - viruses take over the cells of your body and live/reproduce inside the cell causing damage
Who is Ignaz Semmelweis
Identified cause of childbed fever. Emphasized doctor cleanliness
Who is Louis Pasteur?
Discovered microorganisms cause disease and developed vaccines as a cure
What did Joseph Lister do?
Discovered how antiseptics prevented infection
What is agrobacterium tumefaciens?
A tumor-inducing bacteria in plants that has been altered by scientists to transfer traits (genes) from one plant to another
What is herd immunity?
The resistance of a group to an attack by a disease to which a large proportion of the members of the group are immune
What did Alexander Flemming?
Discovered penicillin
Who are Ernest Chain and Howard Florey?
Worked to have penicillin available during WWII as a safe and effective antibiotic treatment
What is carcinogen?
A cancer-causing substance
What is a benign tumour?
A tumour that does not affect surrounding tissues other than by physically crowding them
What is a malignant tumour?
A tumour that interferes with the functioning of surrounding cells ; a cancerous tumour
