Wk 3 Part 1 Cell Structure F24 PDF

Cells  Cell Theory Cells are the fundamental unit of life. All living things are composed of one or more cells. All cells come from existing cells.  Requirements of a Cell 1. Enclosed in a membrane 2. Transportation 3. Ability to carry out energy transformations 4....

Cells  Cell Theory Cells are the fundamental unit of life. All living things are composed of one or more cells. All cells come from existing cells.  Requirements of a Cell 1. Enclosed in a membrane 2. Transportation 3. Ability to carry out energy transformations 4. Information storage and retrieval system 5. Reproduction  Cell Size Cell sizes generally range from 1 – 100 micrometers. Micrometer = 1 x 10–6 m or one-millionth of a meter Figure 3.7 Belk&Borden Human Biology 2009  Cell Size The small size of cells is a function of surface area to volume ratio.  Cell Organelles Cell structures – Organelles = subcellular structures – Each organelle has a specific function. – Organelles work together to keep individual cells healthy and produce required raw materials  Nucleus – Houses the DNA – Serves as the cell’s control center – Surrounded by two membranes, together called the nuclear envelope  Cell Structure Cytosol Cytoplasm  Study Tip: make a table Include each of the organelles we discuss: Nucleus ER (smooth and rough) Golgi Lysosomes Mitochondria For each: Cytoskeleton What is its function? What is its structure? Components? And…  Endoplasmic reticulum (ER) – A network of membranes running from nuclear envelope into cytosol rough ER (RER) smooth ER (SER) – SER is involved in detoxifying harmful substances synthesizing lipids. – RER is  Golgi Apparatus A stack of interconnected membranous sacs Vesicles pinch off from the ER to fuse with the Golgi apparatus and empty their protein contents. – The proteins are then modified, sorted, and sent to their appropriate destination in new vesicles that bud off from the Golgi apparatus. Lysosomes Fig. 3.18 Goodenough & McGuire Biology of Humans 2017  Mitochondria – Manufacture cellular energy – Surrounded by inner and outer membranes separated by the intermembrane space Inner membrane carries proteins involved in adenosine triphosphate (ATP) production  Cytoskeleton – A network of filaments and tubules composed of proteins – Helps a cell maintain its shape and to move  Cytoskeleton Microtubules are involved in the formation of Cilia Flagella Lung epithelial cells Sperm cells  Concept Check 1 The size and number of organelles in a cell often correlates with that cell’s function. First, propose a function for cells that contain extensive rough ER. And then, propose a function for cells that contain a large number of lysosomes Make sure to explain your answer for each.  Plasma Membrane – The outermost boundary of a cell – Isolates the cell’s content from the environment – Serves as a barrier that determines which substances enter and leave the cell  Membrane Structure Plasma and organelle membranes are composed partly of phospholipids – In cells they form a phospholipid bilayer Fig. 3.6 Goodenough & McGuire Biology of Humans 2017  Membrane Function Transporting Substances Across Membranes – Cell membranes are selectively permeable. Figure 3.19 Belk&Borden Human Biology 2009  Membrane Function Passive transport – movement across the plasma membrane in living organisms which does not require energy from the cell Three types: – Diffusion – Facilitated diffusion – Osmosis  Diffusion Diffusion – the movement of molecules from where they are in high concentration to where they are in low concentration  Diffusion What kinds of things can diffuse across a membrane ? 1. 2. 3. What cannot diffuse across a lipid bilayer? 1. 2.  Facilitated Diffusion Molecules unable to diffuse across the membrane can be transported by carrier proteins embedded in the lipid bilayer. – Called facilitated diffusion if it does not require extra energy  Osmosis Osmosis is the passive movement of water across a membrane from an area of high water concentration to an area of low concentration of water. – Direction determined by difference in total solute concentration Lots of solutes in cell, then water will enter cell Lots of solutes in water, then water exits cell – Either has the potential to be a problem for the cell 1. 2.  Membrane Function Active transport: pumping substances across the membrane Used to maintain a concentration gradient Maintaining this difference requires energy Use proteins (“pumps”) to move substances against a concentration gradient.  Transport of Large Molecules Exocytosis: Endocytosis:  Concept Check 2 Compare and contrast facilitated diffusion and active transport.  9/23 Group Discussion 1. Review the Group Discussion Prep Info document to find your group # in this week’s module 2. We’ll relocate to our group spots for discussion and the second half of class Front of room 10 7 4 1 11 8 5 2 12 9 6 3  Group Discussion Prep Activity Upload a copy of the completed google doc Introductions: 1. Your preferred name 2. Your intended major (still deciding is fine) 3. Your plans for what you hope to do after you graduate from Rutgers (again, still deciding is fine) 4. Why you elected to take this course 5. What you are hoping to learn in this course Scheduling: Assign leaders to all of the group discussions Dates: 9/30, 10/14, 10/28, 11/4, 11/18, 12/9