General Biology 1 - Lesson 8.1 Structure & Components of the Cell Membrane PDF

GENERAL BIOLOGY 1 2nd Quarter I S.Y. 2024-2025 LESSON 8.1 STRUCTURE & COMPONENTS OF THE CELL MEMBRANE Prepared by: JAYSON L. LUMAGAS Special Science Teacher I  CLASS SHARING OF CONCEPTS Share three (3) concepts that you know about STRUCTURE &...

GENERAL BIOLOGY 1 2nd Quarter I S.Y. 2024-2025 LESSON 8.1 STRUCTURE & COMPONENTS OF THE CELL MEMBRANE Prepared by: JAYSON L. LUMAGAS Special Science Teacher I  CLASS SHARING OF CONCEPTS Share three (3) concepts that you know about STRUCTURE & COMPONENTS OF THE CELL MEMBRANE. Class Sharing of Concepts PREDICT AND OBSERVE: BREAD AND BUTTER SANDWICH ANALYSIS 1. How do you describe the sandwich? 2. If I put a red dye on the top of the bread, will the water soak through the sandwich? Why or why not? PREDICT AND OBSERVE: BREAD AND BUTTER SANDWICH ANALYSIS 3. What cell organelle does the sandwich represent? Why? PREDICT AND OBSERVE: BREAD AND BUTTER SANDWICH ANALYSIS 4. What if I put olives between the sandwich, will the red dye soak underneath? Why or why not? 5. What do olives represent?  LEARNING COMPETENCIES The learners: 1. describe the structural components of the cell membrane (STEM_BIO11/12-Ig-h-11); and 2. relate the structure and composition of the cell membrane to its function (STEM_BIO11/12-Ig-h-12).  OUTLINE OF LESSON 1 CELL MEMBRANE Structure, Functions, and Components 2 TYPES OF TRANSPORT MECHANISMS A. Passive Transport (Diffusion & Osmosis) B. Active Transport (Primary Active Transport, Secondary Active Transport, and Bulk Transport) 8.1 Structure & Components of the Cell Membrane  LEARNING OBJECTIVES At the end of the session, you are expected to: 1. identify the structural components of the cell membrane and relate the structure to its function; 2. describe the diverse roles of proteins in the membrane; and 3. compare membrane permeability for polar and nonpolar molecules. 1. DESCRIBE THE PICTURE. ACTIVITY 8: BUILD A CELL MEMBRANE ACTIVITY 8: BUILD A CELL MEMBRANE ACTIVITY 8: BUILD A CELL MEMBRANE THE FLUID MOSAIC MODEL OF THE CELL MEMBRANE A “mosaic” of different components – including phospholipids, cholesterol, proteins, and carbohydrates that provides the membrane a fluid character (Nicholson, 2014). Plasma membranes ranges from 5 to 10 nm in thickness. THE FLUID MOSAIC MODEL OF THE CELL MEMBRANE This model was proposed by S. Jonathan Singer and Garth Nicholson in 1972. The lipid content of the membrane is responsible for its fluidity which prevents it from solidifying as external temperatures drop. 2. WHY IT IS CALLED THE FLUID MOSAIC MODEL? It is sometimes referred to as a fluid mosaic because it has many types of molecules which float along the lipids due to the many types of molecules that make up the cell membrane. FLUID MOSAIC MODEL Cell membranes are represented according to a fluid-mosaic model, due to the fact that they are: ❑ Fluid – the phospholipid bilayer is viscous and individual phospholipids can move position. ❑ Mosaic – the phospholipid bilayer is embedded with proteins, resulting in a mosaic of components. FLUID MOSAIC MODEL a. how materials are being transported in the cell membrane b. how cell is being protected c. how cell communicate with other cells  3. What do you think is the relationship between the structure and function of the membrane? How does it contribute to the cell being the fundamental unit of life?  OTHER FUNCTIONS 1. PROTECTION 2. CELL SHAPE 3. COMPARTMENTALIZATION 4. CELL RECOGNITION 5. CELL FUNCTION 6. MATERIAL TRANSPORT  CHARACTERISTICS 1. Is made up of two layers of phospholipids. 2. It has many proteins embedded in it. 3. It is a selectively permeable element that checks and regulates the various substances that comes in and out of the cell. 4. It serves as the based attachment for the cytoskeleton and cell wall of some organisms. Thus, it also supports the cell and maintain the shape of the cell.  4. WHAT ARE THE COMPONENTS OF THE CELL MEMBRANE? Directions: Identify the biomolecule found in cell membranes by unscrambling the letters. SPDIPHSOILPOH PHOSPHOLIPIDS CLUE: a lipid made of glycerol, two fatty acid tails, and a phosphate-linked head group. A. PHOSPHOLIPIDS Phospholipid – a lipid made of glycerol, two fatty acid tails, and a phosphate-linked head group. Pliable – Easily bent Fluid – Able to flow freely  A. PHOSPHOLIPIDS Cell Membrane Lipids – helps in maintaining flexibility Phospholipid molecules have unique attributes that allow them to form a bilayer structures, and they are primarily responsible for the physical properties of biological membranes. A. PHOSPHOLIPIDS This nature of the plasma membrane was first proposed in 1925 by Dutch scientists Evert Gorter and Francois Grendel. A phospholipid is an amphipathic molecule that has both a hydrophilic region (the “water-loving” phosphate head) and a hydrophobic region (the water-fearing” hydrophobic tails).  4. WHAT ARE THE COMPONENTS OF THE CELL MEMBRANE? Directions: Identify the biomolecule found in cell membranes by unscrambling the letters. DASOCTRAYBEHR CARBOHYDRATES CLUE: It is a biomolecule made up of carbon, hydrogen, and oxygen. Sugar, starches and fiber are some of its examples.  B. CARBOHYDRATES CHAINS Carbohydrate groups are present only on the outer surface of the plasma membrane and are attached to proteins, forming glycoproteins, or lipids, forming glycolipids. Mostly found on the external surface. Types: Functions: Glycoproteins - attached to proteins. Forms distinctive cellular markers Glycolipids - attached to lipids. Cell-cell recognition B. CARBOHYDRATES CHAINS The carbohydrate chains occur only on the outside surface of the lipid bilayer or on the peripheral proteins.  4. WHAT ARE THE COMPONENTS OF THE CELL MEMBRANE? Directions: Identify the biomolecule found in cell membranes by unscrambling the letters. ONPIRTES PROTEINS CLUE: These biomolecules are made up of building blocks called amino acids joined by peptide bonds. C. MEMBRANE PROTEINS Types: 1. Integral Proteins 2. Peripheral Proteins Membrane proteins - may extend partway into the plasma membrane, cross the membrane entirely, or be loosely attached to its inside or outside face.  C. MEMBRANE PROTEINS Cell Membrane Proteins – monitor and maintain the chemical climate of the cell and assist in the transfer of molecules across membrane  TYPES OF MEMBRANE PROTEINS 1. Glycoprotein – embedded in the cell membrane, helps in cell to cell communication and transport of molecules. 2. Receptor proteins – helps the cell in communicating with the outside environment through the use of hormones, neurotransmitters, and other signaling molecules. 3. Transport proteins – transport molecules across cell membranes 4. Structural proteins – give the cell support and shape TYPES OF MEMBRANE PROTEINS TYPES OF MEMBRANE PROTEINS TYPES OF MEMBRANE PROTEINS TYPES OF MEMBRANE PROTEINS  4. WHAT ARE THE COMPONENTS OF THE CELL MEMBRANE? Directions: Identify the biomolecule found in cell membranes by unscrambling the letters. LOCRETELHSO CHOLESTEROL CLUE: It is a type of lipid, a waxy substance found in cells. It is essential in the production of other biomolecules like hormones, steroids and Vitamin D. D. CHOLESTEROL Cholesterol - another lipid found alongside phospholipids in the core of the membrane. Regulates the fluidity of the membrane as temperature varies D. CHOLESTEROL Cholesterol - This help in regulating the fluidity of the cell membrane. Glycolipids help the cell to become familiarized with other cells around them.  5. WHAT IS YOUR NOTION OF CHOLESTEROL? Low-density lipoprotein (LDL) cholesterol can clog the arterial walls. Sometimes called the "bad" cholesterol. Despite its harmful effects, cholesterol is an important structural component of the plasma membrane of cells especially in the aspect of membrane fluidity D. CHOLESTEROL D. CHOLESTEROL  D. CHOLESTEROL The presence of double bonds in fatty acids helps maintain membrane fluidity. The more phospholipids with double bonds, the more fluid the cell membrane is. This is because the double bond provides a kink within a monolayer. This prevents all of the phospholipids from packing together really closely and restricting fluidity of the membrane.  D. CHOLESTEROL The presence of double bonds in fatty acids helps maintain membrane fluidity.  D. CHOLESTEROL The presence of double bonds in fatty acids helps maintain membrane fluidity. D. CHOLESTEROL  5. What could be the effect on a cell if one tries to remove the cholesterol in its plasma membrane? If one removes the cholesterol in the plasma membrane of the cell, the fluidity of this cell will be greatly affected. At very high temperatures, the cell will be too fluid; it might result in further disruption. At very low temperatures, the lipid bilayer will tend to become too rigid.  6. How does the plasma membrane permit certain molecules to enter selectively into the cell? The size and the chemical nature of the molecules are important determiners of the permeability of the membrane to certain substances. The molecules that pass through the plasma membrane follow a concentration gradient wherein they move from an area of higher concentration to an area of lower concentration.  PERMEABILITY OF THE CELL MEMBRANE Selectively permeable polar and larger molecules small, non-charged molecules concentration gradient Small, uncharged particles trying to cross the plasma membrane  PERMEABILITY OF THE CELL MEMBRANE Molecules that require energy expenditure for them to be transported across the membrane. PERMEABILITY OF THE CELL MEMBRANE Molecules that are free to move across the membrane.  7. Type 2 diabetes is the most common type of diabetes in which the cells of the body cannot recognize insulin, the hormone that lowers blood sugar level. Explain which proteins in the plasma membrane are most affected and why? The most affected are the receptor proteins in which specific extracellular substances such as hormones bind to. These proteins have certain shapes that allow only specific molecules to bind to them which triggers the change in the cell’s shape to bring about cellular responses. LET’S WRAP IT UP! LET’S WRAP IT UP! The plasma membrane is described by the fluid mosaic model because its structure is composed of diverse protein molecules embedded in a mosaic-like fashion in the fluid phospholipid bilayer. LET’S WRAP IT UP! The phospholipid bilayer is selectively permeable because it only allows certain substances into cells while keeping others out. The size and the chemical nature of the molecules are important determiners of the permeability of the membrane to certain substances.  LET’S REVIEW: Identify the different parts of the cell CARBOHYDRATES membrane. PHOSPHOLIPID BILAYER CHOLESTEROL PERIPHERAL PROTEINS INTEGRAL PROTEINS  LET’S REVIEW! Identify the different parts of the phospholipids. HYDROPHILIC HEAD HYDROPHOBIC TAIL WHAT ARE THE STRUCTURAL COMPONENTS OF CELL MEMBRANE? P – Phospholipids C – Carbohydrate M – Membrane Proteins C – Cholesterol WHAT ARE THE TYPES OF MEMBRANE PROTEINS? “GREATEST [ GRTS ] “ G – Glycoprotein R – Receptor Protein T – Transport Proteins S – Structural Proteins WHAT ARE THE FUNCTIONS OF THE CELL MEMBRANE? P – Protection C – Cell shape C – Compartmentalization C – Cell Recognition C – Cell Function M – MATERIAL TRANSPORT THANK YOU! DO YOU HAVE ANY QUESTIONS?