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Flashcards in 2017 Paper Deck (20):

Difference between cellulose and glycogen

Cellulose is made from beta glucose monomer/glycogen is made from alpha glucose
Glycogen is heavily branched/cellulose forms long straight chains that contain microfibrils to provide strength


Why glycogen is a good storage molecule

Glycogen- alpha glucose with 1-4/1-6 so heavily branched
Readily hydrolyse the glycosidic bonds to give off energy and to produce ATP following aerobic respiration


How mRNA is formed in plants

Helicase breaks hydrogen bonds and separated strands
Strands act as templates
Free flowing nucleotides join exposed bases by complementary base pairing
Catalysed by polymerase
Splicing occurs to remove introns and allow Exxon’s to join together


How is an s shaped curve formed

Binding of first oxygen molecule changes shape and makes it easier for other o2 molecules to bind


Advantage of having adult haemoglobin

Lower affinity, so more oxygen unloaded at repairing tissue so greater respiration


Why antibody is specific

Specific base sequence so specific primary structure
Particular hydrogen-ionic bonds so specific tertiary structure
Binding site only complementary to antigen to form antigen-antibody complex


Cohesion tension theory

Water evaporates from mesophyll cells by transpiration
This lowers water potential
Water enters by xylem
Creates tension
Water is cohesive so dorms a continuous column
Water is pulled upwards from roots to the stem


What is non-disjunction

Failure of separation of chromosomes in meiosis meaning one cell has an extra copy and one is missing one-can lead to e.g. downs and turner respectively


What two adaptations does the cell membrane in the uterine lining have that makes it efficient for nutrient transport

Many protein carriers
Thin membrane


Explain the action of the na/k pump

Both bind to desperate areas, ATP hydrolysis used to change protein shape to move na+ against gradient and k+ out


Increased salt results in tissue fluid build up, explain why?

Salt moves out bc there is a lower wp in tissue fluids, so cannot re-enter, lymphatic system cannot completely drain excess fluid


Describe and explain the advantage of secreting extra cellular proteins

Allows faster breakdown of organic matter to release nitrates


Describe the action of membrane bound dipeptidases and explain the advantage.

Hydrolyse the peptide bind between two amino acids in dipeptide, allows for reabsorption of AA


Describe how bacteria divide

Binary fission, organelles, plasmid and genetic material replicated and then grows and splits


Explain how bacterial resistance arises through natural selection and why two antibiotics should be used

Two should be used as likelihood of being resistant to both is low


Does the data support the conclusion

Yes, no SD overlap, shows that no effect on membrane for wheat but more ions leave for wild oats so membrane disrupted m, loss of ions kills cells so no metabolic reagents


Describe what classification x and y show about evolutionary relationships

One was closely related whereas the other had two distantly related


Describe three ways scientists determine genetic relationships

DNA base sequence
Amino acid sequence
Immunoglobin/cytochrome C comparison


Describe and explain 3 adaptations of tracheal system for gas exchange?


Trachea has cartilage for structural support
Cartilage makes trachea rigid, is c shaped to provide flexibility

The tracheoles do carry some liquid for which oxygen can diffuse from directly into the cells

Muscles in the thorax and abdomen contract and relax causing movements of the abdomen which help ventilate the tracheae and maintain concentration gradient for oxygen
Ventilation of o2/co2

Spiracles can control rate of gas exchange/water loss
Compress trachea to force air in and out


How does the gill larvae help it to be adapted to its behaviour

Counter current
Max o2 absorption for respiration as they actively hunt prey