BIOLOGY SOL INTERACTIVE REVIEW NOTEBOOK UNIT 2 CONCEPTS

BIOLOGY SOL INTERACTIVE REVIEW NOTEBOOK UNIT 2

CONCEPTS COVERED: The History of Cell Studies • 1. Robert Hook (1665) used a microscope to examine a thin slice of cork. The little boxes he observed reminded him of small rooms (cells) in which monks lived. He coined the use of the word “cell”. • 2. Leeuwehoek (1673) was the first to see and describe living cells (microorganisms) in drops of pond water using his single lens microscope.

• 3. Schleiden (1838) was a German botanist who concluded that all plants were made of cells. • 4. Schwann (1839) was a German zoologist who stated that all animals were made of cells. • 5. Virchow (1855) concluded that new cells could be produced only from the division of pre-existing cells. • 6.

Cell Structure 101 • 1. Two categories of cells: prokaryotic & eukaryotic • 2. Cells are placed into these categories based on whether they have a “true” membrane bound nucleus as well as other membrane bound organelles.

• 3. Prokaryotic cells are generally smaller and more primitive than eukaryotic cells. They do not have a true nucleus. They have no membrane bound organelles. Many of their chemical reactions take place along the cell membrane. • 4. Eukaryotic cells are generally larger and more complex than prokaryotic cells. A eukaryotic cell has a nucleus surrounded by a nuclear membrane as well as many membrane bound organelles (mitochondria, chloroplasts, Golgi, ER, vacuoles). • 5. The bacteria and archaebacteria are prokaryotic. • 6. All cells other than bacteria and archaebacterial are eukaryotic. • 7. All cells are surrounded by a barrier called a cell membrane. All cells contain genetic material in the form of DNA.

Animal Cell • • • • 1. cell membrane 2. Golgi apparatus 3. ribosomes 4. endoplasmic reticulum(rough) 5. nucleolus 6. nucleoplasm 7. nuclear membrane 8. vacuole 9. chromosomes 10. lysosome 11. mitochondria 12. endoplasmic reticulum (smooth) 13. cytoplasm 14. centrioles

Plant Cell • 1. chloroplast • 2. nucleus • 3. nucleoli • 4. cytoplasm • 5. cell wall • 6. cell membrane • 7. central vacuole

8. Cell wall, chloroplasts, and central vacuole. 9. The central vacuole is filled with water creating turgor pressure. This aids the cell wall in giving strength and support to the cell.

Concept Covered: The Size of Cells Although there are exceptions, prokaryotes are generally smaller & less complex than eukaryotes. 2. The factor that limits the size of cells is the ration between the volume and the surface area of the cell. 3. As the cell grows, its volume increases more rapidly than its surface area. 4. This is important because the nutrients, water & oxygen that a cell needs must enter through its surface. Therefore, as a cell grows larger, the surface area becomes to small to allow these materials to enter the cell quickly enough to meet the needs of the cell. 1.

#5. The smaller cell will be more efficient at moving in needed materials because it has a high surface area to volume ratio. As seen in the diagram above, materials will move rather into the smaller cell, thereby supplying more of the cell with the materials the cell requires.

Surface Area to Volume Ratio Video Clips: • https: //www. youtube. com/watch? v= Dfm. Dywe 5 h-Y • https: //www. youtube. com/watch? v= NWO 9 nqo. Afxw

Concept Covered: Surface Area to Volume Ratio 1. V = (2 cm) = 8 cm 3 2. Surface area = 6 (2 cm x 2 cm) = 24 cm 2 3. 24/8 = 3: 1 ration 4. Volume = (3 cm) = 27 cm 3 5. Surface area = 6 (3 cm x 3 cm) = 54 cm 2 6. 54/27 = 2: 1 ratio 7. There is a decrease in the surface area to volume ratio as the cell increases in size. 8. As the surface area to volume ratio decreases, it takes longer for the cell to get the nutrients it needs and to get rid of its wastes. This might lead to starvation or poisoning. 9. It divides.

Concept Covered: Cell Internal Organization 1. Basic eukaryotic structure: • Cell membrane: A lipid bilayer that serves as the outer boundary of a cell. • Cytoplasm: the portion of the cell that lies in between the nucleus and the cell membrane. The cytoplasm contains the various organelles of the cell. • Organelles: Structures with highly specialized functions that are found suspended in the cytoplasm of the cell. • Nucleus: contains nearly all of the cell’s DNA which is the coded instructions for making the proteins of the cell.

• 2. Sample Answer-Different jobs are carried out in the different areas of a factory, just as they are in a cell. • 3. Nuclear membrane – A double membrane that encloses the nucleus. It is porous to allow materials and messages to pass in and out. Chromatin – Granular material that consists of DNA tightly coiled around proteins. It condenses during cell division to form chromosomes. Chromosomes – A threadlike structure that contains the genetic information that is passed from one generation to the next. Nucleolous – The site of ribosome production • 4. Chloroplasts & mitochondria.

Concept Covered: The Cell Membrane 1. The cell membrane regulates what enters and leaves the cell. It also provides protection and support to the cell. 2. A “selectively permeable membrane” is a membrane that keeps out some molecules, but allows other to pass through. 3. This is a model of cell membrane structure representing the dynamic of membrane proteins and lipids. According to this model, the lipid bilayer behaves more like a fluid than a solid. Because of this fluidity, the lipids and proteins can move laterally within the lipid bilayer. 4. Cell membrane:

Concept Covered: Ribosomes & ER 1. Ribosomes are not surrounded by a membrane, they consist of 2 subunits – a large and a small subunit. The subunits are composed of proteins & RNA and are manufactured by the nucleolus. Ribosomes play important roles in the synthesis of proteins. 2. Some ribosomes are found free in the cytoplasm of the cell. These ribosomes produce proteins that are to be used within the cytosol. Other ribosomes are attached to the ER. Proteins to be inserted into membranes or exported from the cell are produced by ribosomes that are attached to the ER.

3. The ER (highway system) is a network of tubules and flattened sacs. It consists of channels that are used as paths along which molecules move from one part of the cell to the other. 4. Rough ER has ribosomes attached to it. Rough ER is involved in the synthesis of steroids in gland cells, the regulation of calcium levels in muscle cells, and the breakdown of toxic substances in the liver. 5. Amino Acids are put together in the correct order by ribosomes. Newly formed poly peptides are moved to the ER where the initial folding and shaping of the protein occurs. The protein is then moved to the Golgi for final folding and modifications. The Golgi (UPS Man) prepares the protein for export from the Cell.

Concept Covered: Mitochondria & Chloroplasts • 1. Both organelles are involved in the energy transformation of the cell. Mitochondria convert the energy stored in foods to ATP. Chloroplasts capture the energy from the sun and convert it to the chemical energy stored in molecules of glucose. • 2.

3. The inner membrane of the mitochondria has many folds and loops. These fold and loops are called cristae. The cristae greatly increase the surface area of the inner membrane. Since the chemical reactions of respiration occur along the cristae membrane, this greatly increases the space for these chemical reactions to occur. 4. --------------------} 5. Every chloroplast contains stacks and stacks of thylakoids. Thylakoids contain chlorophyll. They increase the surface area for the absorption of energy from the sun.

Concept Covered: Other Organelles v 1. Golgi apparatus: a stack of membranes in t 5 he cell that modifies, sorts & packages proteins from the ER. v. Vacuole: Cell organelle that stores materials such as water, salts, proteins & carbohydrates. v. Lysosomes: Cell organelle filled with enzymes needed to break down certain materials in the cell. v. Cytoskeleton: A network of protein filaments within some cells that help the cell maintains its shape & is involved in forms of cell movement. v 2. The vacuole is much smaller in animal cells than in plant cells. The large central vacuole or a plant may take up as much as 90% of the cell’s volume, pushing all other organelles up against the cell membrane. The pressure of water in plant cell vacuole creates turgor pressure which aids the cell wall in structure and support.

Concept Covered: Plant vs. Animal Cell • 1. plant cells tend to be “boxy” & have a very definite shape due to the presence of the cell wall. • 2. animal cells are more flexible & have no definite shape due to the absence of the cell wall. • 3. plant cells need much structure & support to enable the plant to stand upright. Animal cells must be flexible to aid in movement • 4. Cell Wall: the cell wall is strong & inflexible. Its function is to give strength & support to the plant cell. • Chloroplasts: contain the green pigment chlorophyll & is the site of photosynthesis in a plant cell. • Central Vacuole: A large vacuole filled primarily with water inside a plant cell. When filled with water, turgor pressure increases. This aides the cell wall in support. • 5. These cell organelle carry out functions that occur only in plant cells.

Turgor pressure Video: https: //www. youtube. com/watch? v=f. Ny. Yu. Var TIQ • Plant vs Animal Cell – Videos: • https: //www. youtube. com/watch? v=-zaf. JKb. MPA 8 • https: //www. youtube. com/watch? v=r. ABKB 5 a. S 2 Zg

Introduction to Cell Division • 1. There are two main reasons why cells divide rather than continuing to grow larger and larger: a) the larger a cell becomes, the more demands the cell places on its DNA. As the cell grows too large, the DNA cannot keep up with the demands of running a larger cell. b) If the cell grows too large, it will have trouble moving enough nutrients and wastes across the cell membrane. The large the surface area to volume ratio, the better.

2. Cell division is a process by which a cell divides into 2 new daughter cells. 3. The mother cell is the original dividing cell. The daughter cells are the result of cell division. 4. The two types of cell division are: a) mitosis: occurs in the somatic (body) cells. b) meiosis: Occurs in the sex cells. 5. Prior to cell division of cells, all DNA must be replicated so that new cell will receive the entire genome.

Concept Covered: The Cell Cycle 1. The cell cycle is the series of events that cells go through as they grow and divide. It is the life of the cell from the time it is formed from a dividing parent cell until its own division into 2 cells. 2. Cell Cycle:

The 5 stages of the cell cycle are: v. G 1 phase: A period of activity where cells do most of their growing. The cell increases in size and synthesizes new proteins and organelles v. S phase: Replication of DNA occurs v. G 2 phase: Molecules & organelles needed for cell division are produced. The cell is preparing to divide. v. MITOSIS – CELL DIVISION of the NUCLEUS v. Cytoknesis: Division of the cytoplasm (you have 2 new somatic or body cells). 3.

Video Clips: Cell Cycle & Mitosis, Meiosis https: //www. youtube. com/watch? v=L 0 k-enzoe. OM https: //www. youtube. com/watch? v=9 ns. Rufogdo. I

Concept Covered: Interphase 1. See picture -} 2. The three stages of interphase are: v. G 2 v. G 1 v. S phase 3. Centrosomes are located just outside of the nucleus. 4. Cells spend most of their life in interphase.

Let’s Draw the Stages of MITOSIS 1. Prophase: chromosomes become distinct from one another. Nucleolus disappears. Chromosomes are huddled up in middle of cell. 2. Metaphase: The pairs of chromatids (chromosomes) are lined up on center of cell. 3. Anaphase: Spindle fibers shorten, pulling the sister chromatids apart and to opposite sides of the cell. 4. Telophase: Cytokinesis begins, the nuclear membrane forms and nucleolus appears. The spindle is disassembled and two daughter cells begin to form.

Concept: Importance of Mitosis 1. The end result is that one cell has divided into two completely identical cells. 2. Mitosis occurs in cells that are part of a tissue. The new daughter cells must be able to carry out the same function as the other cells in that tissue. 3. Mitosis results in asexual reproduction in unicellular organisms. 4. Mitosis results in growth and repair of tissues in multicellular organisms.

Cell Division & Chromosome Number 1. Haploid is the terms used to refer to a cell that contains only a single set of chromosomes. 2. Diploid is the term used to refer to a cell that contains both sets of homologous chromosomes. 3. Sexual 4. Homologous chromosomes are chromosomes of a pair that carry the same genes at the same loci. They are similar in size, shape, & the genes they carry. 5. All somatic cells (body cells) are diploid. 6. The gametes (sex cells) are haploid. 7. Egg & sperm must be haploid so that when the sperm fertilizes the egg, the diploid number will be restored in the zygote. 8. The cells that produce gametes undergo meiosis to produce haploid sex cells.

Concept Covered: Cellular Transport 1 1. Passive transport – movement of substance across the cell membrane without the use of energy. Active Transport – movement of substances across the cell membrane with the use of energy – against a cell gradient. 2. v Osmosis – movement of water from an area of high to low concentration. v Diffusion – the process by which molecules move from an area of high to low concentration. 3. v Hypotonic – When comparing two solutions, the one with the lower solute concentration. v Hypertonic – when comparing two solutions, the one with the greater concentration of solutes. v Isotonic – when comparing two solutions, both have the same solute concentration. 4. True 5. Hypotonic -> Hypertonic

Concept Covered: Cellular Transport 2 1. Facilitated diffusion is the movement of specific molecules across the membranes from a high to low concentration through the channels of transport proteins. It is passive transport. 2. Phagocytosis: cellular eating – the cell surrounds and engulfs a solid particle & packages within a vacuole. Pinocytosis: cellular drinking – the cell surrounds and engulfs solute rich droplets. Exocytosis: Vacuoles fuse with the cell membrane to force the contents of the vacuole out of the cell. 3. The concentration gradient refers to the difference in concentration of a substance across a membrane. 4. In the absence of other forces, materials will move down their concentration gradients. 5. Carrier proteins bind to specific molecules on one side of the membrane and transport the molecule up their concentration gradient t o the other side of the membrane.

Concept Covered: Thinking Critically about Cells 1. Skin cells would have less mitochondria than muscle cells. Muscle cells have a much higher demand for energy (ATP). 2. A) in a hypotonic solution, red blood cells would swell and burst. Cytolosis would occur. B) In a hypertonic solution, red blood cells would lose water and collapse. Plasmolysis would occur. C) In an isotonic solution, red blood cells would neither swell nor shrink in size. 3. A) a hypotonic solution, plant cells would have an increase in a B) hypertonic solution, plant cells would undergo shrinking (plasmolysis).

4. The presence of a nucleus and membrane bound organelles would indicate that the cell is eukaryotic. 5. Cyto means cell. A world list might include: cytoplasm, cytoskeleton, endocytosis, exocytosis, cytolysis, cytokinesis 6. Both cristae and thylakoids increase the surface area for chemical reactions of respiration & photosynthesis.