Plant CellsPlants vs Animals

Plant Organelles & Function

Cell Walls – Composition & Function

Organelles found in both plant and animal cells

Nucleus - control center of the cell Ribosomes – produce protein Golgi Apparatus – packages protein to

stay in the cell Mitochondria – produces ATP

(powerhouse) Endoplasmic reticulum

Rough: packages proteins to leave the cell Smooth: detoxifies poisons in cell

Organelles found only in plants

Cell wall Large central vacuole Plastids

Chloroplast Tonoplast Chromoplast Leucoplast

Plasmodesmata

Cell Wall

Structural and mechanical support. maintain and determine cell shape. Keeps cell from exploding! carbohydrate storage protect against pathogens, dehydration,

and other environmental factors. Made up of 3 layers

Plasmodesmata (plasmodesma)

Plasmodesmata: small channels that connect the cytoplasm of plant cells to each other, forming a living bridge between cells.

Each cell is not completely isolated by the cell wall.

Plastids

Membrane bound organelle with various functions

Chromoplast – red, yellow, orange (caused by pigments – carotene & xanthophyll). Found in flowers & fruit

Leucoplast – colorless (lack of pigment). Storage of starch grains. Found in roots and seeds

Central Vacuole

Surrounded by a membrane called the tonoplast (type of plastid)

Stores water, salts, minerals, proteins, and pigments

Helps with growth & support

Chloroplast – the most important plastid of all!

Double membrane bound (like mitochondria)

Contain their own DNA which allows them to make their own enzymes

Location of photosynthesis Green color comes from pigment

chlorophyll

Basic Plant Cells

1. ParenchymaMost abundantSpherical w/ thin, flexible wallsPrimary function is

photosynthesis and storageExample: flesh of fruit

Basic Plant Cells

2. Collenchyma-Long cells w/unevenly thickened walls-Walls stretch for growth, structures for support-Alive at maturity-Example – celery fibers

Basic Plant Cells

Basic Plant Cells

3. Sclerenchyma thick and rigid cell walls Cytoplasm disentegrates and walls

remain for support at maturity (it’s dead) 2 basic types

Fibers (long and thin) - linen Sclerids (short) - pears

SclerenchymaScleridFiber

Comparison of 3 basic plant cells