Fruit Flashcards
(42 cards)
What is the botanical definition of a fruit?
Organ that carries and protects seeds, can assist seed diversion
What is the botanical definition of a seed?
Offspring resulting from fertilisation of flower, will result in a new plant if sewn in soil under correct conditions
- legumes and nuts are seeds
What is the botanical definition of a vegetable
Vegetative tissues in general
What is the point of fruit?
To make seeds attractive to mammals
How does fruit make seeds attractive to mammals?
It is sweet and tastes nice
Therefore it is eastern and seeds are dispersed = reproduction
What is fruit in culinary terms?
Associated with sweet flavour and found in deserts
What are vegetables in culinary terms?
Associated with savoury Dishes
Name some fruits that are often referred to as vegetables
Tomatoes Peppers Avocado Cucumber Squash Pumpkin
What do plant cells contain that animal cells do not?
- cell wall
- large vacuole
- plastids -> chloroplasts (for photosynthesis), chromoplasts (formed by chloroplasts for colour), amyloplasts (contain starch granules for efficient energy storage)
What is turgor/turgor pressure?
- water pressure in vacuole pushing out onto cell wall
- largely responsible for crunchy and juicy texture = the breaking of the cell walls and splitting of the vacuoles
Name and describe the different layers of an apple
Flesh - cells are spread out and lots of air (float)
Skin- cells closer together, sml epidermal cells
Cuticle - waxy, protects fruit, stops ingress of microbes and oxygen
What are the attractive properties of fruit?
- sweet = subconsciously linked with calories
- aromatic/ fragrant = important for nocturnal animals
- nutritious, colourful, shape, source of water, ethanol
Fruit is only attractive when mature (ripe) as seeds are ready
What is the definition of fruit ripening?
Changes that occur in fruit that result in desirable characteristics for seed dispersal
What happens to the fruit when it ripens?
- gets softer, increases ability to split fruit and get seeds out
- sweetens = more attractive
- Fragrant and bright in colour = attracts animals that will disperse seeds
- increased susceptibility to microbes = due to sugar increase, this is strategic as if not eaten it will rot and release seeds
What decreases when fruit ripens?
Acidity (some will increase but not noticed due to increased sweetness)
Bitterness
What does ethylene do in relation to fruit?
It is a gaseous plant hormone that removes ripening suppression in land plants
What is ethylene?
Smallest plant hormone
Small hydrocarbon gas
Ch2 = ch2
Can travel from fruit to fruit and plant to plant via air
Once a fruit stats to ripen it produces mor of this, it then drifts causing surrounding fruit to ripen - often in direction of wind.
How does ethylene work to ripen fruit?
Binds o receptors at the plasma membrane which leads to a complex signalling cascade and activation of genes expressing enzymes.
- it can penetrate the whole fruit and ripen on the inside via air pockets
What is climacteric ripening?
When something ripens after harvesting
E.g. bananas, avocado, tomato, apples, pears, blueberries, melons
What is non climacteric ripening?
When something will not ripen after harvesting
E.g. citrus, grapes, pineapple, strawberries, peppers
What is climacteric fruit?
Ripening that accelerates in response to the hormone ethylene
What is non climacteric fruit?
Ripening that occurs in response to a number of developmental signals, including ethylene and other factors.
Tend not to produces a lot of ethylene themselves.
What is another word for menopause in human medicine?
Climacteric - a period of intense metabolic activity in the biology of a plant/animal
Outline what happens during climacteric ripening
-ethylene triggers a massive increase in respiration rate
Respirating triggers production of more ethylene (+ve control mechanism)
Burst in metabolism and enzyme activity
-hydrolytic enzymes (breakdown)= pectinases, amylase, a whole pathway to degrade chlorophyll
Synthetic enzymes
-carotenoid and flavonoid synthesis pathways
Ripening happens quickly
Senescence and fruit falling
