Key Stage 5 Scientific Comprehension and Transport

Key Stage 5 …………………………………………………………………………………………………… Scientific comprehension and …………………………………………………………………………………………………… transport across membranes 2) The article states that photosynthesis is inhibited in drought and saline conditions due to a lack of water and CO2. Suggest why CO2 availability to the plant becomes limited in drought Student worksheet conditions.

Comprehension introduction ……………………………………………………………………………………………………

Scientists at the University of Oxford are investigating the role of …………………………………………………………………………………………………… single proteins with the aim of producing crops better able to …………………………………………………………………………………………………… tolerate salty and dry growing conditions. The research has potentially wide-reaching implications for helping to combat the …………………………………………………………………………………………………… developing food security crisis. 3) What are ROS? What is the cause and consequence of their Research is, however, in its early stages and before crops can be formation? genetically engineered to be grown commercially, the action of …………………………………………………………………………………………………… implicated proteins must be understood further. The initial activity of this lesson engages you to analyse the findings of this …………………………………………………………………………………………………… research. …………………………………………………………………………………………………… Task 1: Comprehension questions …………………………………………………………………………………………………… Use the information in the article to answer the following 4) What are the roles of TOC and TIC? questions. …………………………………………………………………………………………………… 1) Briefly outline the causes for concern about the future of food security. Use statistics to support your points. ……………………………………………………………………………………………………

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…………………………………………………………………………………………………… …………………………………………………………………………………………………… www.oxfordsparks.ox.ac.uk/content/hardy-crops-tackle-food-insecurity 5) What has previous research demonstrated about the role of 8) What are the proposed explanations for the results observed? SP1? What additional evidence did the scientists gather to evaluate this proposed mechanism? …………………………………………………………………………………………………… …………………………………………………………………………………………………… …………………………………………………………………………………………………… …………………………………………………………………………………………………… …………………………………………………………………………………………………… …………………………………………………………………………………………………… …………………………………………………………………………………………………… …………………………………………………………………………………………………… 6) What were the three trail groups in the study of the functions of SP1? ……………………………………………………………………………………………………

7) What were the results for the above groups? ……………………………………………………………………………………………………

…………………………………………………………………………………………………… 9) Draw a flow chart to explain the interactions of SP1, TOC, TIC, photosynthetic machinery (proteins) and ROS. ……………………………………………………………………………………………………

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…………………………………………………………………………………………………… www.oxfordsparks.ox.ac.uk/content/hardy-crops-tackle-food-insecurity Movement across membranes 12) What is a concentration gradient?

All living organisms are comprised of cells. Biological …………………………………………………………………………………………………… membranes are a ubiquitous feature of cells as they allow the …………………………………………………………………………………………………… development of uniquely conditioned compartments suitable for a particular function. Membranes achieve this by being …………………………………………………………………………………………………… highly selective about the movement of substances across them.

The article you have just engaged with introduces the concept of 13) What is an electrochemical gradient? translocation machines (translocons) as a method of transporting proteins across membranes. The following activity …………………………………………………………………………………………………… takes the opportunity to review the multitude of transmembrane transport mechanisms encountered across the …………………………………………………………………………………………………… A-level course and explores the need for protein translocons. ……………………………………………………………………………………………………

Task 2: The principles of movement 14) Why can non-polar molecules not experience an electrochemical gradient? Answer the following on the principles governing the movement across biological membranes. ……………………………………………………………………………………………………

10) What sort of molecules can pass membranes? ……………………………………………………………………………………………………

…………………………………………………………………………………………………… 15) What must be provided either directly or indirectly to move molecules against their concentration gradient? 11) What can facilitate transport across membranes for molecules that do not have the above properties? ……………………………………………………………………………………………………

…………………………………………………………………………………………………… www.oxfordsparks.ox.ac.uk/content/hardy-crops-tackle-food-insecurity Task 3: Types of transmembrane movement Transport Type: Simple diffusion For each of the below types of transmembrane transport Properties of molecules involved: mechanism, complete a short information box. To complete, Small non-polar molecules which are able to pass through the you may need to use your textbooks and/or to have access to hydrophobic (non-polar) regions of the phospholipid bilayer. the internet. Source of energy: Passive process – occurs because the molecules move randomly. A basic phospholipid background has been provided. Please add Diagram to / draw over the top of these to complete your diagrams.

- Simple diffusion (example) - Facilitated diffusion - Osmosis - Primary active transport – Uniporter - Primary active transporter – Co-transporter (antiporter) - Secondary active transport - Co-transport (symporter) - Secondary active transport - Co-transport (antiporter) - Exocytosis - Endocytosis (3 types) - Protein translocation via protein translocons Explanation – How does it work and why is it necessary? Particles involved are non-polar and so are able to pass through the hydrophobic (non-polar) region of the phospholipid bilayer. You may find the following sites useful. Particles move from an area of high concentration to an area of low concentration due to random movement. No transmembrane https://www.khanacademy.org/science/biology/membranes- proteins are involved. and-transport https://courses.lumenlearning.com/nemcc-ap/chapter/3204/ https://ib.bioninja.com.au/standard-level/topic-1-cell- Examples in the A-level course: O2 and CO2 moving between the alveoli and the blood biology/14-membrane-transport/types-of-transport.html

www.oxfordsparks.ox.ac.uk/content/hardy-crops-tackle-food-insecurity Transport Type: Transport Type: Facilitated diffusion Osmosis Properties of molecules involved: Properties of molecules involved:

Source of energy: Source of energy:

Diagram: Diagram:

Explanation – How does it work and why is it necessary? Explanation – How does it work and why is it necessary?

Examples in the A-level course: Examples in the A-level course:

www.oxfordsparks.ox.ac.uk/content/hardy-crops-tackle-food-insecurity Transport Type: Transport Type: Primary active transport – Uniporter Primary active transporter – Co-transporter (antiporter) Properties of molecules involved: Properties of molecules involved:

Source of energy: Source of energy:

Diagram: Diagram:

Explanation – How does it work and why is it necessary? Explanation – How does it work and why is it necessary?

Examples in the A-level course: Examples in the A-level course:

www.oxfordsparks.ox.ac.uk/content/hardy-crops-tackle-food-insecurity Transport Type: Transport Type: Secondary active transport – Co-transport (symporter) Secondary active transport - Co-transport (antiporter) Properties of molecules involved: Properties of molecules involved:

Source of energy: Source of energy:

Diagram: Diagram:

Explanation – How does it work and why is it necessary? Explanation – How does it work and why is it necessary?

Examples in the A-level course: Examples in the A-level course:

www.oxfordsparks.ox.ac.uk/content/hardy-crops-tackle-food-insecurity Transport Type: Transport Type: Exocytosis Endocytosis (phagocytosis, pinocytosis & cell mediated endocytosis) Properties of molecules involved: Properties of molecules involved:

Source of energy: Source of energy:

Diagram: Diagram:

Explanation – How does it work and why is it necessary? Explanation – How does it work and why is it necessary?

Examples in the A-level course: Examples in the A-level course:

www.oxfordsparks.ox.ac.uk/content/hardy-crops-tackle-food-insecurity Transport Type: Protein translocation by translocons Properties of molecules involved:

Source of energy:

Diagram:

Explanation – How does it work and why is it necessary?

Examples in the A-level course:

www.oxfordsparks.ox.ac.uk/content/hardy-crops-tackle-food-insecurity