BI111 Lecture Notes - Lecture 16: The Plant Cell, Hemicellulose, Root System
Document Summary
Highly adaptable for photosynthesis and positions flowers for pollination. Bud gives rise to extension of shoot or new, branching shoot. Produces flowers which later produce fruit which hold seeds. Absorbs water and dissolved minerals from soil. Organ/tissue system: body structure that contains two or more types of tissues and have a definite form and function. Tissue: group of one or more types of cells and intercellular substances that function together in one or more specialized tasks. Primary cell wall (surrounding plasma membrane and cell contents) Used for storage and to maintain turgor pressure against the cell wall. Cellulose is a branched polymer made of 7,000- 15,000 glucose molecules per polymer (most abundant organic substance on earth) Hemicellulose is a branching polymer consists of chains of 500-3,000 sugar units. Pectins particularly abundant in the non-woody parts of terrestrial plants. Some plants have lignified secondary cell wall. Cellulose fibres anchored with lignified: stronger and more rigid.
