Exploring the Molecules of Life: Cells and Tissues

1. 2 Lesson 2.1: Molecules of Life Lesson 2.2: Cells Lesson 2.3: Tissues Cells and Tissues

2. Chapter 2: Cells and Tissues Lesson 2.1 Molecules of Life

3. Biochemistry= Study of the molecules of Life • Most Contain CHON, sometimes PS • carbohydrates • proteins • lipids • nucleic acids • water

4. Carbohydrates=FUEL • sugars or starch molecules • saccharides • simple carbohydrates (1-2) • Glucose=Blood sugar • Sucrose=glucose+frucose=di • complex carbohydrates • Polymers of simple sugars • Glycogen from glucose (A) • Starch (P) • Glycogen used for storage • Liver and muscle • Easily broken off

5. Proteins • chains of amino acids • 20 options • Amino group (-NH2) • Acid Group (-COOH) • Enzymes are proteins • Hb is a protein • amino acids linked by peptide bonds • PEPTIDE=short AA chain ( <50) • Polypeptides • Actin/titin (275/ 33,000)

6. Proteins • protein structure • Primary – the sequence of amino acids • Secondary – the shape that occurs between sequences of amino acids ahelix/bsheet • Tertiary – the overall shape of a protein • Quaternary – the protein structure consists of more than one protein Structure, enzymes, carriers collagen, amylase, myoglobin

7. Lipids- CHO • Hydrophobic • fats and oils • fatty acids • Saturated-sb • Unsaturated-db • Glycerides- Store • Glycerol • Mono/di/tri FA • Phospholipids • Phobic tail/philic head • bilayers • steroids • Ring backbone • Cholesterol/estrogen/testosterone

8. Nucleic Acids • chains of nucleotides • Sugar phosphate backbone • DNA- ACTG • Double helix+H bonds • Chromosomes (46/23) • RNA- ACUG • messenger RNA • transfer RNA • ribosomal RNA • Regulatory RNA • ATP • P breakage

9. Water- dihydrogen oxide • Structure of water – Polar • Hydrogen bonding • Good solvent

10. Water - pH • pH is a measure of hydrogen ion concentration; a measure of the acidity or alkalinity of a solution.  • Solutions with a pH less than seven are acidic. • Solutions with a pH greater than seven are basic or alkaline. • A pH level of is 7.0 is defined as 'neutral‘.

11. Chapter 2: Cells and Tissues Lesson 2.2 Cells

12. Cells • anatomy and physiology of a cell • DNA, RNA, and proteins • life cycle of a cell

13. Anatomy and Physiology of Cells • plasma membrane • regulates in and out movement • cytoplasm • liquid and organelles inside cell • nucleus • control center of cell

14. Plasma Membrane Components • The Plasma Membrane is also called the Phospholipid bilayer • Phospholipids contain a hydrophilic head and a nonpolar hydrophobic tail • Hydrogen bonds form between the phospholipid "heads" and the watery environment inside and outside of the cell  • Cholesterol embedded in the membrane makes it stronger and less fluid

15. Membrane Transport • passive • Passive transport is a movement of biochemicals and other atomic or molecular substances across cell membranes. Unlike active transport, it does not require an input of chemical energy, being driven by the growth of entropy of the system. • Ex. diffusion • active • Active transport is the movement of molecules across a cell membrane in the direction against their concentration gradient, i.e. moving from a low concentration to a high concentration. • Ex. sodium-potassium pump

16. Cytoskeleton • strengthens and shapes the cell • Microfilaments, which are the thinnest part of the cytoskeleton, are used to give shape to the cell and support all of its internal parts. • Intermediate filaments are not directly involved in cell movements. Instead, they appear to play basically a structural role by providing mechanical strength to cells and tissues. • Microtubules - Microtubules make up the internal structure of cilia and flagella &provide platforms for intracellular transport and are involved in a variety of cellular processes, including the movement & cell division (mitosis and meiosis).

17. Organelles in the Cytoskeleton • Microvilli - microscopic cellular membrane protrusions that increase the surface area of cells, and are involved in a wide variety of functions, including absorption, secretion,  & cellular adhesion. • Cilia – minute, hairlike structures capable of lashing movement and serves especially in free unicellular organisms to produce locomotion or in higher forms a current of fluid • Centrioles – organelles that cordinate cell division and form the poles during mitosis

18. Mitochondria and Energy • Mitochondria – site of ATP synthesis and cellular respiration within the cell.

19. Golgi Apparatus • Cells synthesize a large number of different macromolecules. The Golgi apparatus is integral in modifying, sorting, and packaging these macromolecules for cell secretion or use within the cell. It primarily modifies proteins delivered from the rough endoplasmic reticulum but is also involved in the transport of lipids around the cell, and the creation of lysosomes. 

20. Ribosomes and Endoplasmic Reticulum • Ribosomes – the sites of protein synthesis where amino acids transported by tRNA are assembled in order, corresponding to the mRNA sequence • Endoplasmic reticulum – a series of membranes that serves as a transport highway through the cell, and may have ribosomes (rough) or lack them (smooth).

21. The Nucleus • The nucleus is a membrane-enclosed organelle found in eukaryotic cells. It contains most of the cell's genetic material, organized as multiple long linear DNA molecules to form chromosomes. The function of the nucleus is to maintain the integrity of these genes and to control the activities of the cell by regulating gene expression. 

22. DNA, RNA, and Proteins • Transcription – DNA making a copy of a gene in the form of mRNA. • Translation – Proteins being made from amino acids assembled at the ribosome in the order determined by the mRNA.

23. Mitosis Cell division

24. Life Cycle of a Cell • Interphase- the longest phase (majority of cell life) • Growth and normal cellular processes • G1- growth (longest part) • S- Synthesis/some duplication • G2- more growth and prepare to divide • Some cells stay in G0- they never divide!

25. Mitosis – Division of the Nuclear Contents • Prophase • chromatin condenses into chromosomes joined at centromeres in middle, nuclear membrane breaks down, microtubules grow from centrioles toward centromeres- will be the spindle fibers • Metaphase • Spindle fibers lock onto centromeres, chromosomes pulled by spindle fibers to line up in the center of the cell. • Anaphase • centromeres are cut in half by separatase, sister chromatids pull toward centrioles • Telophase • chromosomes “decondense,” new nuclear membrane forms, spindle fibers dissolve

26. Cancer • The uncontrolled growth and division of abnormal cells • Normally, your body forms new cells as you need them, to replace old cells that die. • In most cases, the cells that are damaged or have faulty DNA undergo apoptosis- Sometimes this process doesn’t happen, causing a large number of nonfunctional cells- a tumor • Tumors can be benign (stays in one place) or malignant (spreads or metastasizes). .

27. Some thoughts…. • If damaged DNA can be caused by mutations, what can cause mutations? • Some successful cancer treatment drugs work by disrupting mitosis. Why would that be important? • What else would have to happen to “cure” the cancerous cells? .

28. Chapter 2: Cells and Tissues Lesson 2.3 Tissues Cytology- study of cells Histology-study of tissues

29. Types of Tissues Epithelial tissues • Line the cavities and surfaces of structures throughout the body, and also form many glands. • Functions include secretion, selective absorption (barrier), protection, cellular transport and detection of sensation.

30. Connective tissue (CT) supports, connects, or separates different types of tissues and organs of the body. Consists mostly of extracellular matrix found everywhere including in the central nervous system. All CT has three main components: ground substances, fibers and cells. All are immersed in the body fluids. Connective tissue proper, Blood, Bone, Cartilage Types of Tissues

31. Muscle tissue skeletal or striated muscle (attached to bone); smooth or non-striated muscle (hollow or lumen containing organs); and cardiac muscle (also striated-heart only). activated through interaction of the central nervous system. Striated or skeletal muscle only contracts voluntarily Generates force and permits movement Types of Tissues

33. Nervous tissue component of the nervous system, which regulates and controls bodily functions and activity via electrical signals. neurons, or nerve cells, which receive and transmit impulses, and neuroglia, also known as glial cells which assist the propagation of the nerve impulse as well as providing nutrients to the neuron. Types of Tissues

34. Epithelial Cell Shapes • There are three principal morphologies associated with epithelial cells: • Squamous epithelium has cells that are wider than they are tall • Cuboidal epithelium has cells whose height and width are approximately the same • Columnar epithelium has cells taller than they are wide (column-shaped).

35. Epithelial Cell Arrangement • simple • one layer • stratified • more than one layer • Ex: skin • other • transitional • stretchable

36. Epithelial Glands • Glandular epithelial cells (glands) are specialized epithelial cells that secrete bodily products, sometimes called simply glands. • These differ from glandular organs- large conglomerates of glands with blood supply and CT • Endocrine Glands vs Exocrine Glands Endocrine glands have secretions directed into the extracellular fluid (basal side), move into interstitial space to the vascular system Exocrine Glands have secretions released to the apical cell surface, move out of ducts to outside environment

37. Connective Tissue • Functions • strengthens the body and organs • protects internal organs • maintains the shape of organs • provides rigid framework for muscles to pull

38. Classes of Connective Tissue • Connective tissue proper- wide variety of locations and functions including immune defenses. • Cartilage- provides support and flexibility and minimizes friction. • Bone tissue (osseous tissue)- provides framework, protects organs, & supports the body.

39. Blood provides transportation, regulation, and protection. Blood carries oxygen and nutrients to the cells and carries carbon dioxide and metabolic wastes away from the cells. Blood – Tissue or not?

40. CT Proper Loose Connective Tissue • Areolar, reticular (as in the spleen) & adipose tissue (fat). • Loose connective tissue is named based on the "hair weave" and type of its constituent fibers. Gives support and strength. There are three main types: • Collagenous fibers: made of collagen and consist of bundles of fibrils that are coils of collagen molecules. • Elastic fibers: made of elastin and are "stretchable." • Reticular fibers: consist of one or more types of very thin collagen fibers. They join connective tissues to other tissues like in the LN, bone marrow and spleen.

41. CT Proper Dense Connective Tissue • Regular, Irregular and elastic • large, robust fibers that impart to these tissues considerable strength and elasticity.   • contain either collagen or elastic protein fibers.   • The collagenous types, far more abundant, are also called fibrous or "white" connective tissues. • Elastic fibers, on the other hand appear yellow in unstained tissues and are commonly referred to as "yellow" connective tissue.

42. Cartilage Formed by chondroblasts and found in many body locales where support, flexibility, and resistance to compression are important. • Unlike bone and all other connective tissue types, cartilage is avascular,  lacking blood vessels.   • No regenerative capacity   • nutrient delivery is essential for tissue repair.  Blood vessels provide the nutrient delivery to most tissues. • Cartilage contains a gelatinous ground substance called chondroitin sulfate.   • Embedded within the ground substance are collagen and elastic protein fibers.   • matrix is flexible, yet very durable and also resistant to compression forces.  

43. Cartilage 3 varieties of cartilage: • Hyaline: The most abundant type, found in the nose, ears, trachea, larynx, and smaller respiratory tubes and covering the articular surfaces of bones in synovial joints. It reduces friction and acts as shock-absorbing  tissue. • Elastic: More elastic fibers allows for more flexibility. Found in the ear and epiglottis • Fibrocartilage: more collagen allows for more tensile strength. Found in discs in between the vertebrae and knees   

44. Hyaline, Elastic and Fibrocartilage!

45. Bone (Osseous tissue) • major structural and supportive connective tissue of the body.  The matrix contains abundant collagen fibers and these impart strength, some flex, and resistance to twisting or torsional forces.   • Surrounding these "reinforcing rods" of collagen is a cement-like ground substance called hydroxyapatite.   • This mineral complex of calcium phosphate salts makes bone highly resistant to compression forces.   • Together, collagen fibers and hydroxyapatite make bone one of the strongest and lightest materials known.

46. Osseous tissue • Osseous tissue forms the variety of bones that make up the skeletal system.  As such, osseous tissue directly or indirectly contributes to some very important body functions that include: • support - for muscles, organs, and soft tissues • leverage and movement - the synovial joints • protection - for critical organs • calcium phosphate storage - mineral balance • hematopoiesis - formation of blood cells

47. Compact Bone vs Spongey (Trabecular) • Compact bone is a very dense tissue • forming the outer layer of all bones and the thickened shafts or diaphyses of long bones.   • In a microscopic view, compact bone always contains numerous osteons or Haversian Systems. • Cancellous or spongey bone is found forming the core of most flat and irregular bones.   • It is also very prevalent in the epiphyses (ends) of long bones.  The construction of this osseous tissue type is quite different than that of compact bone.   • One key difference is the absence of osteons