INPS School Shakhbout Biology Final Exam Study Materials 2024-2025 PDF

INPS School Shakhbout – Middle & High Section Science Department (2024-2025) Final Exam Study Materials Semester 1 Subject : Biology Grade 9 Lessons Standards...

INPS School Shakhbout – Middle & High Section Science Department (2024-2025) Final Exam Study Materials Semester 1 Subject : Biology Grade 9 Lessons Standards Objectives Lesson 1: Lipids 1. Describe the distinct properties of lipids, including their SCI-HS-PS1-6 hydrophobic nature and roles in energy storage, insulation, and cell membrane structure. 2. Compare the structures and characteristics of saturated and unsaturated fatty acids, explaining how these differences affect their physical properties and roles in the body. 3. Distinguish between natural steroids and synthetic anabolic steroids, discussing the health risks associated with the misuse of anabolic steroids Lesson 2: Proteins SCI-HS-PS1-6 1. Describe the levels of protein structure (primary, secondary, tertiary, and quaternary) and explain how the three-dimensional structure of a protein determines its function in biological systems. Lesson 3: Nucleic Acid SCI-HS-PS1-6 1. Describe and compare the structures of DNA and RNA, highlighting their roles in genetic information storage and protein synthesis. Lesson 4: The two Major SCI-HS-PS1-2 1. Compare prokaryotic cells versus eukaryotic cells, categories of cell 2. Compare plant cells versus animal cells, 3. Compare light micrographs versus electron micrographs, highlighting key similarities and differences. Lesson 5: Membrane SCI-HS-PS1-2 1. Describe the structure of cell membranes and explain structure why they are referred to as "fluid mosaics" Lesson 1 : Lipids Lipids: are fatty compounds that perform a variety of functions in your body. Lipids are polymer of fatty acids and glycerol. Lipids share common characteristics , they are hydrophobic ( water -fear) which make them insoluble in water There are 4 major types of Lipids Types of Where to Find Chemical composition Lipids Fats- Animal source and 3- Fatty acids and Triglyceride Oils – Plants source glycerol Plasma membrane 2-fatty acids Phospholipids Glycerol Phosphate groups Steroids Plants ,animals 4 – Fused carbon rings Example of steroids ( Growth hormone) Waxes Plant leaves , Ear waxes 4 – Fused carbon rings and honeycomb Saturated and Unsaturated fatty acids Unsaturated fats contain one or more double bonds in their structure Saturated fatty acids are made up of a carbon chain with no double bonds. Phospholipids (PL) are a group of polar lipids that consist of two fatty acids, a glycerol unit and a phosphate group There are two types o steriods a. Natural Steroids : Natural steroids are a class of organic compounds with a core structure of four fused carbon rings b. Synthetic Anabolic steroids : Anabolic steroids are drugs made in a lab that mimic the naturally occurring hormones called androgens Criteria Natural Steroids Anabolic Steroids Function promote the growth of skeletal build muscle tissue, among other important muscle and the development of bodily processes. male characteristics for conditions such as, certain cancers, or acquired immunodeficiency syndrome (AIDS) Medical Use used to reduce inflammation, and treat Treat cancer or AIDS conditions such as asthma. Potential Misuse immunosuppression, weight gain, Anabolic steroid misuse is also osteoporosis, and high blood pressure when linked to addiction, depression, and taken over long periods. aggressive behavior (sometimes called "roid rage". Lesson 2 : Proteins : Proteins are polymers that are made of amino acids The four parts of amino acids: Central Carbon atom make four covalent bond with: 1. A carboxyl group (-COOH) 2. An amino group (-NH₂) 3. A hydrogen atom (H) 4. A side chain (R group), which varies between amino acids The side chain (R group) is the variable component that gives each amino acid its distinct chemical properties. There are 20 types of Amino Acid, each type of amino acid has a unique side chain which gives that amino acid its special chemical properties. a hydrophobic side chain, meaning it repels water, while a hydrophilic side chain interacts and attracts water. This difference influences how these amino acids interact within a protein's structure, affecting folding and positioning. Types of Proteins Protein Shape and Structure Proteins are formed when two amino acids join together through a dehydration reaction. In this process, the amino group of one amino acid reacts with the carboxyl group of another amino acid, and a molecule of water (H₂O) is removed. This creates a peptide bond, linking the two amino acids. 4 levels of Protein Structure Level 2: The secondary Level 3:The tertiary Level 1:The Level 4: The quaternary structure happens structure is when the primary structure structure is when multiple when that chain folds whole chain folds into a is like a chain of chains (proteins) join into simple shapes like 3D structure. amino acids. together to form a larger, spirals and sheets. functional complex. Changing in amino acid may alter the shape of the protein which change its structure A protein’s shape is sensitive to the environment. An unfavorable change in temperature, pH, or some other factor can cause a protein to unravel (lose its structure) For example : a. Normal hemoglobin. Red blood cells of humans normally disck -shaped.Each cell contains millions of molecules of the protien hemoglobin, which transports oxygen from the lungs to other organs of the body. Lesson 3: Nucleic Acids Nucleic acid : A polymer consisting of many nucleotide monomer; serves as blueprint for proteins and through the actions of proteins , for all cellular structures and activities. Nucleic acids Macromolecules that: 1) store information and genetic information. 2) provide the instructions for building proteins. 3) tell your cells what to do to keep you alive and healthy. They consist of two types DNA (deoxyribonucleic acid) RNA (ribonucleic acid) Nucleic acids are polymers made from monomers called nucleotides. Each nucleotide has three parts: 1. a five-carbon sugar, 2. a phosphate group, and a nitrogen- containing base.  Each DNA nucleotide has one of four possible nitrogenous bases: 1. adenine (A), 2. guanine (G), 3. thymine (T), or 4. cytosine (C). ‒ A molecule of cellular DNA is double-stranded, with two polynucleotide strands coiled around each other to form a double helix. ‒ Bases along one DNA strand hydrogen-bond to bases along the other strand. ‒ The functional groups hanging off the base determine which bases pair up: A only pairs with T and G can only pair with C. Comparison between DNA and RNA Both DNA and RNA are polymers of nucleotides and both are made of nucleotides consisting of a sugar, a phosphate, and a base.  The genetic material that humans and all other organisms inherit from their parents consists of giant molecules of DNA. The DNA resides in the cell as one or more very long fibers called chromosomes. A gene is a unit of inheritance encoded in a specific stretch of DNA that programs the amino acid sequence of a polypeptide. Building a protein (How do DNA and RNA build up Protein? ) Lesson 4 : The Two Major Categories of Cells The Microscopic World of Cells Organisms are either single-celled, such as most prokaryotes and protists, or multicellular, such as plants, animals, and most fungi. The accumulation of scientific evidence led to the cell theory which states that: a) All living things are composed of cells b) The cell is the basic living unit of organization for all organisms c) All cells come from other cells Prokaryotic cells versus Eukaryotic cells Biologists classify all life into three major groups called domains. – Organisms of the domains Bacteria and Archaea are composed of prokaryotic cells. – Organisms of the domain Eukarya—including protists, plants, fungi, and animals—are composed of eukaryotic cells. Prokaryotic cells Vs. Eukaryotic cells Similarities between Prokaryotic cells and Eukaryotic cells 1. Plasma Membrane Role: Acts as a barrier, regulating the movement of molecules in and out of the cell to maintain homeostasis. 2. Cytosol or ( also known as cytoplasmic matrix) Role: A jelly-like fluid that suspends cellular components, allowing metabolic reactions and molecular movement within the cell. 3. Chromosomes Role: Contain genetic material (DNA) with genes that instruct cellular functions and direct protein synthesis. 4. Ribosomes Role: Build proteins by translating genetic instructions from DNA, crucial for cell structure and function. An overview of Eukaryotic cells (Plants and Animal cells) Common Parts of Animal and Plant Cells 1. Plasma membrane Function : Acts as a barrier, regulating the movement of molecules in and out of the cell to maintain homeostasis 2. Cytoplasm It is the fluid substance that fills the cell. All the cell organelles are suspended in the cytoplasm. Function: The cytoplasm maintains the osmotic concentration of the cells and prevents them from bursting or shrinking. 3. Nucleus → It is a membrane bound organelle, spherical in shape. Most of the activities of the cell is directed by the nucleus. Function: The nucleus is the control center of the cell. – Each gene is a stretch of DNA that stores the information necessary to produce a protein. – Proteins do most of the actual work of the cell. The nucleus is separated from the cytoplasm by a double membrane called the nuclear envelope. Pores in the envelope allow certain materials to pass between the nucleus and the surrounding cytoplasm. 4. Nucleolus a prominent structure within the nucleus, Function: it aids in protein formation and RNA synthesis. 5. Mitochondria – are found in almost all eukaryotic cells, – are the organelles in which cellular respiration takes place, and – produce ATP from the energy of food molecules. Cells use molecules of ATP as the direct energy source for most of their work. 6.The endoplasmic reticulum (ER) is one of the main manufacturing facilities in a cell. The ER – produces an enormous variety of molecules, – is connected to the nuclear envelope, and – is composed of interconnected rough and smooth ER that have different structures and functions. 7. Golgi Apparatus They are flattened stacks of membrane bound sacs. It looks like the ER, and are located near the nucleus. Function: Its function is to modify proteins made by the cell and pack and export proteins to the cell parts. 8. Ribosomes Function : Build proteins by translating genetic instructions from DNA, crucial for cell structure and function. 9. Vacuole A compartment covered by a single membrane. They are organelles for storage Function : Stores water, food, or waste for the cells. Only in Plant Cells 1. Cell Wall It is a rigid layer that surrounds the plant cells. Its main function is to provide rigidity, strength, protection against mechanical stress and infection. 2. Chloroplasts It is an elongated or disc- shaped organelle containing chlorophyll. It is the site for photosynthesis in a plant cell. 3. Plastids Plastids are storage organelles. They store products like starch for synthesis of fatty acids and terpenes. Only in Animal Cells 1. Lysosomes A membrane bound organelles that contain digestive enzymes. They break down the waste products and detoxify the cell. 2. Centrioles Are organelles that become prominent only during cell division. It functions as the anchor for the cytoskeletons. Lesson 5 : Membrane structure 1. The plasma membrane separates the living cell from its nonliving surroundings. 2. The plasma membrane and other membranes of the cell are composed mostly of phospholipids, arranged into a two-layer sheet called a phospholipid bilayer. 3. The Plasma membrane possesses the property of selective permeability. (Selectively permeable means some substances are able to pass through the membrane, while other substances are not able to pass through) The plasma membrane is a fluid mosaic: – fluid because molecules can move freely past one another and – a mosaic because of the diversity of proteins in the membrane. The primary components of the plasma membrane a. The plasma membrane and other membranes of the cell are composed mostly of phospholipids, arranged into a two-layer sheet called a phospholipid bilayer b. Carbohydrates c. Proteins d. Cholesterol Cell Surface ( How do the cell surfaces of plant cell and animal cells differ?) Plant cells have a cell wall made of cellulose fibers. Plant cell walls protect the cells, maintain cell shape, and keep cells from absorbing too much water. Animal cells lack cell walls and most secrete a sticky coat made of proteins and other molecules that surround, support and give the structure to cells and tissues in the body is called the extracellular matrix. The extracellular matrix helps cells attach to, and communicate with, nearby cells, and plays an important role in cell growth, cell movement, and other cell functions. In addition, the surfaces of most animal cells contain cell junctions, structures that connect cells together into tissues, allowing the cells to function in a coordinated way.