Cell Inclusions and Vacuolar Contents

what is a cell?

membrane bound structure containing biomolecules, such as nucleic acids, proteins, and polysaccharides

prokaryotic cells

bacteria

eukaryotic cells

plant or animal cells

genes

store genetic information

ribosomes

synthesise proteins

ATP

main source of metabolic energy that sustains various cellular processes

cell membrane

controls flow of substance in and out of cell

difference between prokaryotes and eukaryotes?

eukaryotes have a membranous nuclear envelope

nucleus

Control center of the cell

rough endoplasmic reticulum

protein synthesis

smooth endoplasmic reticulum

lipid synthesis

Golgi apparatus

packages and secretes proteins

Lysosomes

contain digestive enzymes

mitochondria

ATP production

centrioles

aids in cell division

what materials are essential to all living organisms?

proteins, carbohydrates, lipids

what are in plant but not animal cells?

cell wall, chloroplast, vacuole

cell wall

provides structure and support

primary cell walls

flexible and distortable during growth

secondary cell wall

rigid, incrusted with strengthening material (lignin, suberin)

lignin

Allows plants to grow upright

where is lignin commonly found?

wood

where is suberin commonly found?

cork

suberin

Fatty material found in cell walls

plant wax

outer layer of cell wall

plant wax cotains

hydrocarbons, sterols, fatty acids/alcohols/esters, decomposition products

what can plant wax be used for?

to classify plants

taxonomy

The science of classifying organisms into different families

symbiotic relationship

living conjugation of several units that used to be individual units

chloroplast

site of photosynthesis and ATP production

what do chloroplasts contain?

DNA and ribosomes

chloroplast structure

double membrane, stroma, thylakoids, grana, plastoglobules, plastid DNA

stroma

aqueous matrix

thylakoids

A flattened membrane sac inside the chloroplast, used to convert light energy to chemical energy.

grana

stacks of thylakoids

plastoglobules

lipid droplets

main product of photosynthesis

carbohydrates with hydrocarbon chain of 4-7 carbon atoms

glucose

C6H12O6

products of photosynthesis

oxygen, ATP, reduction power

light reactions of photosynthesis

photons are provided by light, in conjunction with nutrients from soil and water produce ATP.

ATP is only produced

in the light photosynthesis reaction

photosystem 1 wavelength

P700-wavelength best absorbed

photosystem 2 wavelength

P680- wavelength best absorbed

process of light photosynthesis

PS2 = light hits reaction centre (absorbs 680nm) excites chlorophyll which loses electrons, water is split to replace electrons giving oxygen and protons. pheophytin. the electrons travel down electron transport chain via electron carrier, while generating ATP to hit PS1. light hits PS1, electrons get re-excited and form NADPH using H+ and NAPD+. phytotoxin.

non-cyclic photophosphorylation

the synthesis of ATP and reduced NADP involving photosystems 1 and 2.

cyclic phosphorylation

The generation of ATP by cyclic electron flow using only photosystem 1.

dark reactions of photosynthesis

ATP, carbon dioxide and reduction power produce sugars.

where do light reactions occur

chlorophyll/thylakoid membrane

where do dark reactions occur

stroma

importance of light reactions

production of NADPH and protons that are used in the first step of dark reactions

Calvin Cycle

reactions of photosynthesis in which energy from ATP and NADPH is used to build high-energy compounds such as sugars

phases of Calvin cycle

carbon fixation, reduction, regeneration

process of carbon fixation

3 CO2 molecules binds a 5-carbon molecule of RuBP to form an unstable 6 carbon intermediate which breaks down to form two 3-phosphoglyceric acid (3PGA) molecules.

calvin cycle is catalysed by?

RuBP carboxylase/oxygenase (rubisco)

process of reduction

energy from ATP converts the 3-PGA molecules into a three-carbon sugar glyceraldehyde-3-phosphate (G3P)

enzyme for reduction phase

glyceraldehyde 3-phosphate dehydrogenase

regeneration

Some G3P is utilized in making glucose, while others are recycled to continue the cycle by combining with a carbon acceptor that turns into RuBP. Energy comes from ATP.

C3 plants

present in cool, wet climates, photorespiration occurs using standard Calvin cycle

C4 plants

found tropically, higher photosynthetic rate due to increased release of carbon dioxide

CAM plants

desert plants close their stomata during the day, collect CO2 at night, and store the CO2 in the form of acids until it is needed during the day for photosynthesis

central vacuole

membrane-bound, fluid filled sac that stores cell inclusions such as pigments, water, salts and toxins in the form of crystals

where is malate stored

vacuole

high levels of calcium oxalate in plants

toxic to humans

raphide crystals

needle-like, cause irritation/toxicity

druse crystals

star-shaped, many faceted

dumbcane

proteolytic enzyme

silica bodies

found in grasses

anthocyanins

water-soluble, stored in vacuole, responsible for red/blue/purple colours

amyloplasts

Membrane‑bound organelles containing concentric layers of starch

where is amyloplast commonly found?

tubers (potato), storage roots (sweet potato), bananas

leaves contain

no starch

hilum

indent

what can be used to identify types of starch?

shape, size, hilum, position

greenery indicates

poor photophosphorylation

oxygen in photosynthesis

waste

oxygen is a

paradox. necessary to be kept alive but also ultimately kills

wrinkles

oxygen attacking lipids in the body

chronic conditions are

have an underlying condition of oxidative stress and must have an imbalance to curve the excess of free radicals

secondary metabolism

enzymes/antioxidants in the body