Title [ Q1W3 ] General Biology Transes.pdf ✅

CHAPTER 3: A TOUR OF THE EUKARYOTIC CELL In-Depth Discussion About Eukaryotic Cells GBIO I S.Y. ‘23-24 SHS STEM S1Q1 WEEK 3 | CAMPBELL BIOLOGY 8TH ED. | CAMPBELL & REECE Illustration 1.0. A Panoramic View of the Eukaryotic Animal Cell (Notes on Page 3 onwards) WONRIKA ON X | SHS STEM NOTES | CAMPBELL BIO 8TH ED. GENERAL BIOLOGY I SEM1 Q1 PAGE 1
CHAPTER 3: A TOUR OF THE EUKARYOTIC CELL In-Depth Discussion About Eukaryotic Cells GBIO I S.Y. ‘23-24 SHS STEM S1Q1 WEEK 3 | CAMPBELL BIOLOGY 8TH ED. | CAMPBELL & REECE Illustration 1.1. A Panoramic View of the Eukaryotic Plant Cell (Notes on Page 3 onwards) WONRIKA ON X | SHS STEM NOTES | CAMPBELL BIO 8TH ED. GENERAL BIOLOGY I SEM1 Q1 PAGE 2
CHAPTER 3: A TOUR OF THE EUKARYOTIC CELL In-Depth Discussion About Eukaryotic Cells GBIO I S.Y. ‘23-24 SHS STEM S1Q1 WEEK 3 | CAMPBELL BIOLOGY 8TH ED. | CAMPBELL & REECE 03 CELL STRUCTURE PART II PPT & LECTURE CAMPBELL BIO 03 TRIVIA: WHY ARE CELLS SMALL? Introduction to Cell Structure Part II ● As a cell increases in size, its surface area grows slower than its volume. ● A larger cell size results in a less efficient diffusion, or in simpler terms, it becomes slower for the cell to transport food and other molecules. COMPARING SURFACE AREA & VOLUME LARGE CELL SMALL CELL Decreased Surface Area : Volume Ratio Increased Surface Area : Volume Ratio Less efficient diffusion More efficient diffusion 1.0 COMMON FEATURES OF ANIMAL & PLANT CELLS 1.1 PLASMA MEMBRANE ● The plasma membrane is the cell’s recognition and communication center. ● Selective permeable barrier that allows passage of enough oxygen, nutrients, and wastes to service the entire cell. ● Has membrane proteins suspended to it. ● Material/Structure: Phospholipid bilayer (referred in the Fluid Mosaic Model) PHOSPHOLIPID BILAYER ● From the word “bilayer,” it comes with two layers: 1. Phospholipids 2. Membrane Proteins ● Each phospholipid molecule contains: a. Two hydrophobic (water-hating) tails b. Two hydrophilic (water-loving) head ● This makes phospholipids as amphipathic molecules. ● An in-depth discussion about the structure of the plasma membrane will be administered in the next academic quarter. 1.2 NUCLEUS ● Nucleus is the cell’s information center. WONRIKA ON X | SHS STEM NOTES | CAMPBELL BIO 8TH ED. GENERAL BIOLOGY I SEM1 Q1 PAGE 3
CHAPTER 3: A TOUR OF THE EUKARYOTIC CELL In-Depth Discussion About Eukaryotic Cells GBIO I S.Y. ‘23-24 SHS STEM S1Q1 WEEK 3 | CAMPBELL BIOLOGY 8TH ED. | CAMPBELL & REECE ● The nuclear envelope encloses the nucleus, separating its contents from the cytoplasm. ● The inner side of the envelope is lined by nuclear lamina: protein filaments that maintain the shape of the nucleus. ● Within the nucleus, the DNA is organized into discrete chromosomes. ● Inside the nucleus is a nucleolus: a dense area where ribosomal RNA (rRNA) is synthesized from genes in the DNA. - Also, large subunits of ribosomes are assembled here. These subunits then leave through the pores. ● The nucleus also directs protein synthesis by synthesizing messenger RNA (mRNA). 1.3 RIBOSOMES ● Ribosomes carry out protein synthesis. ● Cells with high rates of protein synthesis have a large number of ribosomes and prominent nucleoli. - Human pancreas cell is an example: it has a few million ribosomes. ● Ribosomes reside in two regions: 1. Free ribosomes 2. Bound ribosomes TWO TYPES OF RIBOSOMES Free Ribosomes ● Suspended in the cytosol. ● Proteins produced by them mostly function within the cytosol. Bound Ribosomes ● Attached to the outside of the endoplasmic reticulum or nuclear envelope. ● They generally make proteins that are destined for insertion into membranes, or for secretion. 1.4 CYTOPLASM ● Cytoplasm refers to all the material within a cell, enclosed by the cell membrane and except for the cell’s nucleus. ● Cytoplasm and cytosol are two different parts. TYPES OF DIGESTIVE COMPARTMENTS Cytoplasm ● Cytosol + Organelles Cytosol ● Gel-like fluid substance surrounding the organelles. 1.5 VACUOLE Central Vacuole in Plant Cells ● Vacuole is generally used for temporary storage and transport. ● They are large vesicles derived from the endoplasmic reticulum and Golgi apparatus. I VACUOLE IN EUKARYOTIC CELLS Vacuoles in a Eukaryotic Animal Cell ● Employs “phagocytosis (cell eating).” ● e.g. Amoeba gets food via phagocytosis. Vacuoles in a Eukaryotic Plant Cell ● Biggest structure inside the plant cell. ● Maintains turgor pressure to help in providing shape to the cell. ● Storage of water and food. 1.6 CYTOSKELETON ● Cytoskeleton gives mechanical support to the cell and maintains its shape, which is especially important to animal cells (since they lack cell walls). ● Group of fibers that organize themselves in the cell to keep the cell in shape, intact, and on hold. ● There are three main types of cytoskeleton: - Microtubules: thickest - Microfilaments: thinnest - Intermediate filaments: middle range WONRIKA ON X | SHS STEM NOTES | CAMPBELL BIO 8TH ED. GENERAL BIOLOGY I SEM1 Q1 PAGE 4