Ch 6 seaweeds

• Primary producers• Autotrophs• Macrophytes• Macroalgae

General Structure page 103

• Thallus- complete body• Blades-leaf like portions of thallus. Large SA

for photosynthesis• Pneumatocytes-gas filled bladders keeping

blades close to the surface for photosynthesis• Stipe-stem-like structure for support• Holdfast-root like structures for attachment

• Seaweeds lack true leaves, stems, and roots

General structure

Types of seaweed

• Green algae• Brown algae• Red algae

• Requires chemical analysis to distinguish pigments

• KINGDOM PROTISTA, NOT PLANTAE

Facts about seaweed

• http://www.seaweed.ie/

• Algae are plant-like microorganisms that preceded plants in developing photosynthesis, the ability to turn sunlight into energy. Algae cells contain light-absorbing chloroplasts and produce oxygen through photosynthesis.

• Although plants generally get the credit for producing the oxygen we breathe, some 75% or more of the oxygen in the planet’s atmosphere is actually produced by photosynthetic algae and cyanobacteria

• Algae also play an important role as the foundation for the aquatic food chain. All higher aquatic life forms depend either directly or indirectly on microscopic gardens of algae.

Green Algae

• Mostly freshwater and terrestrial• 10% of 7,000 species are marine

Brown algae

• The color of brown algae is due to a yellow brown pigment: fucoxanthin

• Dominant primary producers on temperate and polar rocky coasts and include the largest and most complex seaweeds

Brown algae- Kelp

• Most complex and largest of all brown algae• Temperate and subpolar latitudes• Blades are harvested for food• Kelp bed or kelp forests page 106• 30-80 meters in length• Can grow ½ meter per day

Kelp

Giant kelp forest

• http://www.youtube.com/watch?v=U81p4cb9mwI&feature=fvwrel

• http://www.youtube.com/watch?v=GcbU4bfkDA4&feature=related

Kelp reproduction

• Alternation of generations:• It is a type of life cycle found in some algae,

fungi, and all plants where an organism alternates between a haploid (n) gametophyte generation and a diploid (2n) sporophyte generation

• All plants undergo a life cycle that takes them through both haploid and diploid generations. The multicellular diploid plant structure is called the sporophyte, which produces spores through meiotic (asexual) division. The multicellular haploid plant structure is called the gametophyte, which is formed from the spore and give rise to the haploid gametes. The fluctuation between these diploid and haploid stages that occurs in plants is called the alternation of generations

Alternation of generations

Products containing kelp

• YOUR JOB IN YOUR JOURNAL- HOMEWORK• Alginate• Carrageenan• Beta Carotene

Health Benefits of Kelp

• http://www.advancedbionutritionals.com/Special-Offers/Alginol-ABALGINPPC.htm?gclid=CJ7DwePNuLMCFQvznAod-nEAJQ

• http://www.healthdiaries.com/eatthis/8-health-benefits-of-kelp.html

Kelp Beauty Supplies

• Hair growth:• http://www.livestrong.com/article/158317-kel

p-for-hair-growth-does-it-work/• Seaweed Baths:• http://www.seaweed.ie/baths/index.php

Octonauts : Kelp Forest 10:00min

• http://www.youtube.com/watch?v=1IzdsxmCaY0

Red Algae

• There are more species of marine red algae than of marine green and brown algae combined

• 4000 species• A photosynthetic red pigment, phycoerythrin,

allows them to thrive in deep waters where sunlight is scarce.

Examples of Red Algae

• Coralline algae, Irish moss, gigartina are some types of red marine algae. Coralline algae is one of the main components of coral reefs.

• The combination of milk protein with the algal polysaccharides produce carrageenan, a common thickening agent. Modern uses include ice cream, whipped cream, chocolate milk, thick fruit syrups and many others. Pharmaceutical gels, lotions and toothpaste also benefit from carrageenan

• Kelp, a common name for a number or red and brown, leafy seaweeds, has been a staple food, often called nori in Asia, for thousands of years

• NORI chips!!!!

• Nori, sesame oil, sesame seeds, garlic powder

Seaweed Recipes

• http://www.oceanvegetables.com/seaweed-recipes.html

Economic importance

• Good source of vitamins (B12), minerals, fiber, antioxidants

• Biofuels

What are biofuels??

• http://ngm.nationalgeographic.com/2007/10/biofuels/biofuels-interactive

biofuel

• Hopes are to derive ethanol directly from kelp• The “struggle” is finding a microbe to ferment

alginate• Estimate: seaweed growing in less than 3% of

waters could produce enough ethanol to replace 60 billion gallons of fossil fuels

• The kelp would be cultivated not taken from the wild

Seaweed: Biofuels

• Ted Talk:• http://www.ted.com/talks/jonathan_trent_en

ergy_from_floating_algae_pods.html• 14:46• “Energy from floating algae ponds”

Seagrasses, cordgrasses, mangroves

• Seagrasses- Plants adapted to water. Not true grass

• Cordgrasses are true members of the grass family. Land species tolerant of salt. Do not tolerate total submergence by seawater. Live in salt marshes

• Mangroves- trees and shrubs adapted to live along tropical and subtropical shores