Greetings

Good Afternoon class

PrayerHeavenly Father up abovePlease give us wisdom, strength and loveKeep us always in the right trackAnd open Your door every time we knockThis wisdom is for our study sakeThe strength is for the trials We will take Your love is to everyone to shareAMEN.

Motivation

THE CELLS(Plant Cell & Animal

Cell)Structure and

Functions

Plant Cell

Animal Cell

Terminologies• Organelles

- internal compartments- discrete structures of specific functions- provide a “division of labor” that makes a plant more efficient- examples: nucleus, vacuole

Terminologies….• Cytoplasm

- the materials inside the cell membrane but outside the nucleus

• Cytosol- the semifluid matrix that surrounds and bathes the organelles outside the nucleus

Terminologies…• Protoplast

- the entire plant cell from the cell membrane inward

• Cell Wall- assembles from cellulose and other polymers produced by the plant cell (cell product)- considered to be extracellular; outside the protoplast

Plant Cell Structures and Functions• The Cell Membrane

- a highly remarkably changeable and multipurpose membrane

- supports and defines the plant cell protoplast- regulates the flux of molecules into and out of the cell interior- selectively permeable

- receives chemical and environmental signals from outside the cell which can change cellular activities- accepts raw materials from the

membranes inside the cell and directs the assembly of these materials into cell walls

Plant Cell Structures and Functions

• The Nucleus - surrounded by a double membrane called the nuclear envelope which has pores to allow passage of materials in and out of the nucleus- contains most of the cell’s DNA (chloroplasts and mitochondria contain some DNA), which occurs with proteins in threadlike structures called chromosomes

Chromosomes – contain genes, which are sequences of DNA; that directs most of the activities of the cells via the synthesis of RNA.

Plant Cell Structures and Functions

• Endoplasmic reticulum (smooth and rough)

- rough ER is a major region of protein synthesis in a cell- smooth ER helps make phospholipids and assemble new membranes- extends from the nucleus through cytoplasm in any one cell and from one cell to the next through protoplasmic connections (plasmodesmata)

• Golgi Bodies (Dictyosomes)

- concerned with cellular secretions

- their activity is associated with new cell walls when they are laid down as a partition between two newly divided cells

Plant Cell Structures and Functions• Vacuoles

- help regulate the water content of the plant cells and contain numerous enzymes and pigments- its membrane is called tonoplast- as plant cell grows, most of their enlargement results from the absorption of water by vacuoles- pigments in vacuoles such as red and blue anthocyanins impart bright colors to flowers, fruits and other plant parts- some plant vacuoles harbor toxic chemicals that will deter insects and other animals from eating plants that contain them

Plant Cell Structures and Functions

• Ribosomes- the workbench for protein synthesis- very small and consist of approximately equal amounts of protein and RNA- unlike nucleus and other organelles ribosomes are not surrounded by membranes thus some biologists do not considered them as organelles

Plant Cell Structures and Functions

• Mitochnodria- organelles of energy conversion needed for

cellular metabolism- considered as the powerhouse of the cell because it converts energy stored in the sugars produced during photosynthesis to ATP that powers much of the work of the cell- contains a small amount of DNA and RNA and ribosomes that synthsize some of the enzymes specific to each organelle- grow and divide on their own

Plant Cell Structures and Functions• Chloroplasts

- an organelle of energy conversion- sites of photosynthesis in plant cells- the chlorophylls in them trap the light to fix (capture and integrate) carbon dioxide into sugars- use light energy to make amino acids and fatty acids from carbon fixed via photosynthesis

Plant Cell Structures and Functions

• Lysosomes- contains various enzymes- act as cellular scavengers, digesting cytoplasmic particles such as mitochondria which have passed usefulness- they may also bring about dissolution of entire cells

Plant Cell Structures and Functions• The Cytoskeleton

- very tiny structures which can only be seen under an electronic microscope- forms a network and support system within the cell- performs the following:a. help maintain organelle position and organization within the cell; direct cell expansion and control the movement of chromosomes during nuclear division; andb. transports large molecules within the cell (for some filaments)

ActivityGiven the following words in the box.

Put each word in the Venn Diagram that correspond to the correct answer.

Cell Wall Endoplasmic Reticulum Golgi Complex Centrioles Chloroplast Cell Membrane Lysosome Cytoplasm Vacoule Ribosomes Mitochondria Nucleus

Venn Diagram

EvaluationA. Choose the letter of the best answer. Write

the chosen letter on a ½ crosswise sheet of paper.

1. Where is the site of protein synthesis?a. Nucleus c. ribosomeb. lysosome d. mitochondria

2. Plant cells often have a box-like shape because of thea. nucleus c. cytoplasmb. cell wall d. cell membrane

3. Which of the following is found in the nucleus?a. vacuoles c. mitochondriab. chloroplasts d. chromosomes

4. Digestive enzymes or hydrolytic enzymes are terms associated witha. ribosomes c. golgi apparatusb. lysosomes d. smooth ER

5. What site regulates what goes in and out of the cell?a. cell wall c. cell membraneb. Vacuole d. nuclear membrane

B. Draw and label the different part of the cell either plant cell or animal cell.

AssignmentThought Questions:1. What is the selective advantage of

the small size of cells compared to the large size of organisms?

2. What is the evolutionary advantage of secondary cell walls?

Prepared byJoy Clearth A. Padro

BSEd 3.02Biological Sciences