MODULE 2 – PLANT CELLS AND TISSUES
PARTS OF A PLANT CELL c. ENDOPLASMIC RETICULUM
Starting from the outermost part - a complex system of membranes,
tubules, cisternae and vesicles
1. CELL WALL - two types:
- outermost layer
- almost all plant cells have cell walls, (1) SMOOTH ER
except for the sperm cells of some seed - consists of interconnected
plants. vesicles and cisternae that DO
- arranged in layers and contains: NOT contain ribosomes.
cellulose, microfibrils, hemicellulose, - involved in sterol biosynthesis,
pectin, lignin, and soluble protein. detoxification reactions and fatty
- organized into three major layers: the acid desaturation
primary cell wall, the middle lamella, (2) ROUGH ER
and the secondary cell wall (not - ribosomes attached
pictured). - has a role in protein biosynthesis
- surrounds the plasma membrane and - site where amino acids are
provides the cell tensile strength and assembled in a specific sequence
protection. to produce polypeptide chains.
2. PLASMODESMATA d. RIBOSOMES
- gated plant cell wall channels – - are particles that contain RNA and
- allow the trafficking of molecules proteins, synthesize proteins.
between cells - proteins they create in RER are either
- connects two plant cells secreted or incorporated into
- play important roles during plant membranes in the cell.
development and in the orchestration of
cellular and systemic signaling e. MICROBODIES [CYTOSOME]
responses during interactions of plants - found in plants and animals
with the biotic and abiotic environment. - include:
3. PLASMA MEMBRANE (1) PEROXISOMES
- also known as the plasmalemma. - where photorespiration occurs
- composed of a double layer of - present in eukaryotic cells
phospholipids and associated proteins - contain enzymes involved in a
- its chemical composition is vital in the variety of metabolic reactions
transport process.
- contains: (2) GLYSOSOMES
- specialized peroxisomes
Molecular pumps - convert fatty acid to carbohydrat
- keep substances moving by actively
pumping them in and out of the cell. f. PLASTIDS
- diverse group of organelles
4. CYTOPLASM - play central roles in plant metabolism
- jelly-like fluid that surrounds and via the processes of photosynthesis,
protects the organelles lipid and amino acid synthesis, and
- largest part of the cell and surrounded nitrogen and sulfur assimilation.
by plasma membrane. - surrounded by two membranes
a. MITOCHONDRIA (1) OUTER MEMBRANE
- where cellular respiration takes place - is permeable to small organic
- energy released from broken down molecules
sugars, starches, and amino acids are
broken down and the is used to (2) INNER MEMBRANE
synthesize new compounds that are - less permeable and studded with
both highly energetic and very reactive. transport proteins.
- most common compound is adenosine
triphosphate (ATP) - example of plastid is:
b. DICTYOSOMES (GOLGI BODIES) CHLOROPLASTS
- consists of disk-shaped sacs that are - have a third internal membrane:
stacked-up together in a flat or cup-
shaped array close to the ER. o THYLAKOID MEMBRANE
- two poles of a Golgi stack are: - is extensively folded and appears as
stacks of flattened disks in electron
(1) CIS-FACE (FORMING FACE) micrographs
- located near ER - contains the light-harvesting complex,
including pigments such as chlorophyll
(2) TRANS FACE (MATURING FACE)
PARTS OF A PLANT CELL c. ENDOPLASMIC RETICULUM
Starting from the outermost part - a complex system of membranes,
tubules, cisternae and vesicles
1. CELL WALL - two types:
- outermost layer
- almost all plant cells have cell walls, (1) SMOOTH ER
except for the sperm cells of some seed - consists of interconnected
plants. vesicles and cisternae that DO
- arranged in layers and contains: NOT contain ribosomes.
cellulose, microfibrils, hemicellulose, - involved in sterol biosynthesis,
pectin, lignin, and soluble protein. detoxification reactions and fatty
- organized into three major layers: the acid desaturation
primary cell wall, the middle lamella, (2) ROUGH ER
and the secondary cell wall (not - ribosomes attached
pictured). - has a role in protein biosynthesis
- surrounds the plasma membrane and - site where amino acids are
provides the cell tensile strength and assembled in a specific sequence
protection. to produce polypeptide chains.
2. PLASMODESMATA d. RIBOSOMES
- gated plant cell wall channels – - are particles that contain RNA and
- allow the trafficking of molecules proteins, synthesize proteins.
between cells - proteins they create in RER are either
- connects two plant cells secreted or incorporated into
- play important roles during plant membranes in the cell.
development and in the orchestration of
cellular and systemic signaling e. MICROBODIES [CYTOSOME]
responses during interactions of plants - found in plants and animals
with the biotic and abiotic environment. - include:
3. PLASMA MEMBRANE (1) PEROXISOMES
- also known as the plasmalemma. - where photorespiration occurs
- composed of a double layer of - present in eukaryotic cells
phospholipids and associated proteins - contain enzymes involved in a
- its chemical composition is vital in the variety of metabolic reactions
transport process.
- contains: (2) GLYSOSOMES
- specialized peroxisomes
Molecular pumps - convert fatty acid to carbohydrat
- keep substances moving by actively
pumping them in and out of the cell. f. PLASTIDS
- diverse group of organelles
4. CYTOPLASM - play central roles in plant metabolism
- jelly-like fluid that surrounds and via the processes of photosynthesis,
protects the organelles lipid and amino acid synthesis, and
- largest part of the cell and surrounded nitrogen and sulfur assimilation.
by plasma membrane. - surrounded by two membranes
a. MITOCHONDRIA (1) OUTER MEMBRANE
- where cellular respiration takes place - is permeable to small organic
- energy released from broken down molecules
sugars, starches, and amino acids are
broken down and the is used to (2) INNER MEMBRANE
synthesize new compounds that are - less permeable and studded with
both highly energetic and very reactive. transport proteins.
- most common compound is adenosine
triphosphate (ATP) - example of plastid is:
b. DICTYOSOMES (GOLGI BODIES) CHLOROPLASTS
- consists of disk-shaped sacs that are - have a third internal membrane:
stacked-up together in a flat or cup-
shaped array close to the ER. o THYLAKOID MEMBRANE
- two poles of a Golgi stack are: - is extensively folded and appears as
stacks of flattened disks in electron
(1) CIS-FACE (FORMING FACE) micrographs
- located near ER - contains the light-harvesting complex,
including pigments such as chlorophyll
(2) TRANS FACE (MATURING FACE)
