The Cell - Lecture 3: Introduction, Organelles, and Types - PDF

Lecture 3: The cell Today’s special 1. Review Kahoot! 2. Levels of organization 3. Introduction to the cell 4. Eukaryotic versus prokaryotic cells 5. Cell components (the plasma membrane will be covered in more detail later) Levels of organization: Pair and Share...

Lecture 3: The cell Today’s special 1. Review Kahoot! 2. Levels of organization 3. Introduction to the cell 4. Eukaryotic versus prokaryotic cells 5. Cell components (the plasma membrane will be covered in more detail later) Levels of organization: Pair and Share 1. Think of one example of an organelle (think macromolecules) 2. Think of one example of a cell type 3. Think of one example of a tissue type 4. Think of one example of an organ 5. Think of one example of an organ system Cells are the smallest living things ▪ The cell theory is a fundamental organizing principle of biology that states the following: The cell is the smallest unit of life Cells make up all living things, including unicellular and multicellular organisms New cells can arise only from preexisting cells ▪ There are two basic types of cells: Prokaryotic Eukaryotic Prokaryotes are simple while Eukaryotes are more complex Prokaryotes are simple organisms without Eukaryotes are often more complex (multicellular a nucleus such as bacteria organisms) with a nucleus Prokaryotic cells have more basic structure Some cellular components that ALL cells have 1. Plasma membrane 2. Cytoplasm 3. Genetic material 4. Ribosomes 5. Energy requirements  1. The Plasma membrane is a specialized barrier needed to keep certain things out - Is a selectively permeable membrane - Is involved in connecting cells together - communication through receptors 2. The cytoplasm is the substance inside the cell membrane Includes the cytosol AND organelles (if eukaryotic) 3. Genetic Material DNA is the genetic material containing our genetic make-up or “blue print” It contains a sequence that makes us who we are determining things like eye colour, hair colour, personality traits, susceptibility to disease Behaviour and Genetics For behavioural trait Behaviour and Genetics Identical Twin studies show that behaviour is largely genetic There are differing views regarding the ability to “fight” against our genes Theodosius Dobzhansky stated that “give one hundred children and based on the environment I shall make them geniuses or criminals”; other geneticists stated that “heredity offers us only the roadmap, the environment deciding to get to destination” (Scripcaru and Ast r stoae, 2003, p.36). Conclusions? We have a tendency to behave a certain way based on what genes we get from our parents To be continued… 4. Ribosomes make proteins Examples of proteins made by ribosomes: - Hormones - Receptors - Cell membrane components - Etc. 5. All cells have a need to make energy (ATP) to survive Prokaryotes have fewer, more basic organelles Eukaryotes have more complex organelles Prokaryotes versus Eukaryotes Table 3.1 Review of Features of Prokaryotic and Eukaryotic Cells Feature Prokaryotic Cells Eukaryotic Cells Organisms Bacteria, archaea Plants, animals, fungi, protists Size 1-10 µm across mumacros 10-100 µm across mumacros Membrane-bound Absent Present DNA form Circular Coiled, linear strands DNA location Cytoplasm Nucleus Internal membranes Rare Many Cytoskeleton Present Present Basic Eukaryotic cell structures 1. Nucleus * 2. Golgi Apparatus 3. Mitochondria 4. Lysosomes 5. Endoplasmic reticulum Rough ER Smooth ER 1. The Nucleus is the control centre of a eukaryotic cell ▪ Nucleus Contains almost all of the genetic information of the cell, DNA Surrounded by nuclear envelope, a double membrane that allows communication through nuclear pores The genetic information is organized into chromosomes ▪ Chromosomes are threadlike structures made of DNA, and associated proteins called histones ▪ Humans have 46 chromosomes (23 pairs) in the loose form (chromatin) or condensed, which are then visible in the light microscope during cell division The nucleus is the largest organelle The nucleus contains the DNA found in the form of chromosomes 2. The Golgi Complex modifies proteins made by the cell and produces lysosomal enzymes ▪ Golgi complex A series of interconnected, flattened membranous sacs Proteins are packaged in vesicles and transferred to the Golgi complex for processing and packaging ▪ Lysosomes Contain about 40 digestive enzymes that break down macromolecules, old organelles, and invaders The golgi complex 3. The mitochondria are the powerhouses of the cell ▪ Mitochondria Sites of cellular respiration, providing cell with energy through the breakdown of glucose to produce ATP ▪ Double-membrane organelle ▪ Contain inner foldings, called cristae, that provide increased membrane surface for cellular respiration ▪ Singular: mitochondrion 3. The mitochondrion 4. Lysosomes contain powerful enzymes that can kill the cell Used to destroy bacteria engulfed by phagocytosis (more on this next lecture) Considered suicide packets that contain enzymes that can kill the cell if necessary 5. The ER produces proteins, lipids and carbohydrates ▪ Endoplasmic reticulum An extensive network of channels connected to the plasma membrane, the nuclear envelope, and certain organelles Two types of endoplasmic reticulum: ▪ Rough endoplasmic reticulum (R ER) Contains ribosomes that guide the production of cell products ▪ Smooth endoplasmic reticulum (SER) Lacks ribosomes Involved in the production of phospholipids and detoxification The endoplasmic reticulum can be smooth or rough Cells can have different structures based on their designated function Identify these eukaryotic cells Name the labelled organelles and state their primary function E A B F C D G Many similar cells working together will form _________ (level of organization) Examples: Connective tissue is the tissue that you find between organs to link them together Epithelial tissue is the tissue that you find at the surface of cavities, for example lining the inside of your mouth or blood vessels Muscular tissue is the tissue forming your muscles Nervous tissue is the tissue forming your brain, spinal cord and nerves Adipose (fat) tissue is the tissue forming your fat By the end of this lecture you should Identify the organelles of a cell State the main function(s) for each Distinguish between a eukaryotic and a prokaryotic cell Appreciate our cells and all that they do for us ☺ Lecture 2: Introduction to Organ systems and Homeostasis The hierarchy or levels of organization 1. Atoms and molecules 2. Macromolecules 3. Organelle 4. Tissue 5. Organ 6. Organ system organism Progressive levels of organization within the body THE SMALLEST particles are the building blocks for larger ones… The smallest parts of the body are the Atoms that make up the molecules. Molecules have larger chemical groupings are combined to make an organelle within the cell (ex Golgi) Cells then organize and differentiate together to form a Tissue Tissues then combine with other tissues to form an organ Groups of organs work together to form a system The 11 systems are put together to form an organism Atoms and molecules Atoms – basic unit of matter – smallest component of molecules Molecules – made up of atoms – smallest unit of a chemical compound – examples: water (H2O), Carbohydrates, Lipids, Nucleic Acids, Protein etc. Macromolecules make up cell components Macromolecules are the building blocks of cellular components called organelles Made up of smaller molecules Organelles are the components of cells Different structures within cells that have specialized functions Do all cells contain the same organelles? Consider different functions  Cells combine to form tissues Smallest unit capable of all the properties of life Made up of molecules and organelles In a multicellular organisms cells may have specialized structure and function Tissues are made up of cells and combine to form organs Groups of a particular type of cell that perform a specific function 4 basic types: epithelial, connective, muscular, nervous Examples: muscle, bone, blood  Organs are made of tissues and are part of organ systems Groups of different tissues that perform a specific function Examples: - Kidneys - Stomach - Heart Organ Systems are made of different organs and combine to form an organism Groups of organs that work together to perform a specific function E.g. the digestive system There are 11 organ systems that we’ll consider How many can you name?  Organ systems: (a) The Integumentary System Function: Components: - Cutaneous membrane (epidermis and dermis) - Hair follicles (hair and sebaceous glands) - Nails - Sensory receptors (touch, pressure, temperature, pain) - Subcutaneous layer (attaches skin to deeper structures)  Organ systems: (b) The Skeletal System Function: Provides support; protects tissues; stores minerals; forms blood Components: Bones, cartilages, and joints: - Axial skeleton(skull, vertebrae, ribs, sternum, sacrum, cartilages, and ligaments ) - Appendicular skeleton (limbs and supporting bones and ligaments) Bone marrow  Organ systems: (c) The Muscular System Function: Produces movement and locomotion; provides support; generates heat Components: Skeletal muscles - Axial muscles (support and position axial skeleton) - Appendicular muscles - (support, move, and brace limbs) Tendons  Organ systems: (d) The Nervous System Function: Directs immediate response to stimuli, usually by coordinating the activities of other organ systems Components: Central Nervous System Peripheral Nervous System  Organ systems: (e) The Endocrine System Function: Components: - Pineal gland - Pituitary gland - Thyroid gland - Parathyroid glands - Thymus - Adrenal glands - Kidneys - Pancreas - Gonads (testis/ovaries)  Organ systems: (f) The Cardiovascular System Function: Transports cells and dissolved substances including nutrients, wastes, and gases Components: Heart Blood vessels - Arteries - Capillaries - Veins Blood  Organ systems: (g) The Lymphoid System Function: Components: - Lymphatic vessels - Lymph nodes - Spleen - Thymus  Organ systems: (h) The Respiratory System Function: Delivers air to sites where gas exchange can occur between the air and circulating blood Components: - Nasal cavities, paranasal sinuses - Pharynx - Larynx - Trachea - Bronchi - Lungs (alveoli)  Organ systems: (i) The Digestive System Function: Components: - Salivary glands - Pharynx - Esophagus - Stomach - Small intestine - Liver - Gallbladder - Pancreas - Large intestine  Organ systems: (j) The Urinary System Function: Components: - Kidneys - Ureters - Urinary bladder - Urethra  Organ systems: (k) The Reproductive System (male) Function: Produces sex cells and hormones Components: Accessory organs - Epididymides - Ductus deferens - Seminal glands - Prostate gland - Urethra External Genitalia - Penis - scrotum  Organ Systems (k): The Reproductive System (female) Function: Produces sex cells and hormones Components: - Ovaries - Uterine tubes - Uterus - Vagina - External genitalia (clitoris, labia) - Mammary glands Homeostasis Homeostasis: all body systems working together to maintain a relatively stable internal environment Systems respond to external and internal changes to function within a normal range (body temperature, fluid balance) The basis for physiology Homeostasis allows for an internal state of relatively constancy despite external variation Homeostasis Receptor Receives the stimulus Control Center Processes the signal and sends instructions to effector Effector Carries out instructions Negative versus Negative feedback positive feedback Positive feedback - Reduces or suppresses the original - Accelerates or enhances the stimulus output created by a stimulus - Re-set physiological variables - Amplify or reinforce the change that is occurring - Disrupt homeostasis - Reverses a change in the controlled variable, bringing it back to normal - - Rare, but important Maintains homeostasis – E.g. child birth, blood clotting – E.g. Blood sugar levels, body temperature Negative feedback: Thermoregulation Besides Body Temperature, what else must be kept within homeostatic range? The Big Picture Systems integration Systems work together to maintain homeostasis Homeostasis is a state of equilibrium Opposing forces are in balance Physiological systems work to restore balance Failure results in disease or death You should now be able to List the different systems and know their main components Describe negative feedback and how it is essential to homeostasis Lecture 1: Introduction Course: BIO101-B11 Behavioural Biology Teacher: Christine Lafleur Class: Monday 11:30-13:00 in 4A.5 Lab section 01: Thursday 8:30-10:00 5A.14 Lab section 02: Thursday 10:00-11:30 5A.14 Humans in the World of Biology Outline: Basic Characteristics of All Living Things Evolution: A Unifying Theme in Biology Levels of Biological Organization Tissues Organs and organ systems Biology is the study of life Bios=Life Involves the syudy of life and organisms (structure and function, chemical composition, development and evolution) Vast with many branches Based on: Cell: basic unit of life Genes: Basic unit of heredity Evolution: Propels the creation of new species Living versus non-living What are the properties of life? To be considered living, something must 1. contain the same macromolecules 2. Be composed of cells 3. grow and reproduce 4. use energy 5. respond to their environment 6. maintain homeostasis 7. Evolve and adapt 1. Living things contain the same macromolecules Proteins Carbohydrates Lipids Nucleic acos 2. Living Things are made of cells All living things are composed of cells Cells are the smallest units of life All cells arise from preexisting cells Living things use energy and raw materials to carry out metabolism Metabolism refers to all of the chemical reactions that occur within the cells of living things Cells can be Simple Prokaryotes or more complex Eukaryotes The diversity of cells in the human body 2. Living things are composed of cells. These are red blood cells (disks) and a white blood cells (sphere). 3. Living things grow and reproduce Living things grow and reproduce. All organisms reproduce their own kind.  Reproduction can be sexual or Asexual Asexual reproduction produces identical clones Sexual reproduction involves the fusion of 2 cells to give rise to an organism with greater genetic diversity 4. Living things use energy  5. Living things respond to stimuli ▪ All living things Respond to their environment Millipede curling up for protection Sunflowers facing the sun Stimulus: heat Response: drop pan 6. Living things maintain homeostasis. This person’s body temperature will remain about 37C Homeostasis ▪ Homeostasis is the constant adjustment made by the organ systems to respond to changes in the internal and external environments while limiting too large variations of the internal condition required for life Depends on the nervous and endocrine systems, which are mostly responsible for internal communication Maintained primarily through negative feedback mechanisms ▪ Negative feedback mechanisms Corrective measures that slow or reverse variation from a normal value Once the normal value is reached, corrective measures cease ▪ Positive feedback mechanisms Cause a change that promotes continued change in the same direction  Homeostasis is a state of relative constancy Receptor: receives the stimulus Control centre: processes the signal and sends instructions Effector: Carries out instructions Homeostasis: The internal environment remains ”relatively” stable despite fluctuations in the external environment Homeostasis involves negative feedback to re-set a certain variable such as body temperature Negative Feedback control systems Are essential for maintaining homeostasis Are inhibitory Act to re-set physiological variables Are much more common than positive feedback control systems Figure 4.12 Hypothalamus and Body Temperature ▪ In this system Receptors = thermoreceptors Control center = hypothalamus, a region of the brain Effectors = sweat glands, blood vessels in the skin, as well as skeletal muscles ▪ Hyperthermia and hypothermia are life-threatening conditions Hyperthermia: abnormally elevated body temperature Hypothermia: abnormally low body temperature Figure 4.13  Positive feedback is rare and moves variables away from homeostasis Positive feedback control systems - are stimulatory - Amplify or reinforce the change that is occuring - Tend to produce destabilizing effects and disrupt homeostasis - Bring specific body functions to swift completion - Ex: blood clotting, child birth - Child birth demonstrates positive feedback 7. Population of living things evolve and have adaptive traits. The orchid is adapted to live perched on branches of trees. It uses other plants for support so that it can receive enough sunlight to produce its own food by photosynthesis.  Scientists organize living organisms in a system that demonstrates a way to demonstrate evolutionary relationships Evolution: A Organisms with the greatest similarity are grouped together Unifying Several classification systems have been proposed; the latest includes three domains Theme in Humans are unique because they Have a relatively large brain Biology Stand upright on two legs Have opposable thumbs Let’s try to summarize the properties of life Levels of Biological Organization Atoms are units of matter that cannot be broken down any further Cells, the smallest units of life, are composed of molecules, the chemical components of cells Cells may contain organelles that carry out specific functions Cells with the same function are grouped into tissues Two or more tissues working toward the same function are organs At least two organs working together to perform a function form an organ system An individual is a single organism made of organ systems Levels of Biological Organization Many individuals of the same species living together in a common geographical area are called a population When several populations interact, they form a community A community and its physical environment are called an ecosystem All organisms exist within the much larger biosphere, the part of Earth where life is found Levels of Biological organization Cells combine to form Tissues There are 4 types of tissues in the body: -epithelial -connective tissue -muscle -nervous These tissues combine to form organs  Tissues combine to form organs Organs are made of different tissues Let’s name the 12 Body systems and give one major component and a function of each 1. 4. 2. 5. 3. 6. Let’s name the 12 Body systems and give one major component and a function of each 7. 10. 8. 11. 9. 12. Figure 4.7 What is Behavioural Biology? “Behavioural biology examines the behaviour of humans and animals and investigates which behaviour is innate and which skills are learned in the course of life.” Why is biology important to behaviour? According to scientists, there are 2 main factors that determine the way we are: Nature: the way we are based on our genes (genetics will be covered later) Nurture: The way we are based on our environment and experiences Each one has multiple factors to consider https://www.youtube.com/watch?app=de sktop&v=tbSgU41FIac  Summary: Bad mothering leads to anxious and stressed offspring as “Grandma’s regulated by methylation of the experiences glucocorticoid receptor Leave a Mark (hypermethylation) on Your They found that the same poor Genes” mothering behaviour was passed onto the grand offspring as was regulated by the estrogen receptor By Michael Meaney (Neurobiologist at McGill) and Mosche Syzf (molecular biologist and geneticist at McGill) 41 You Should Now Be Able To: ▪ List the characteristics of life. ▪ Describe how evolutionary relationships are reflected in modern systems of classification. ▪ Define homeostasis and explain its importance to life. ▪ Describe and exemplify a negative feedback system. ▪ Understand positive feedback systems ▪ Understand why biology is an important component of behaviour