Week 2 - Cellular & Tissue Levels of Organization Flashcards
1
Q
What are the 6 criteria of life?
A
- Organization
- Metabolism
- Exchange of material
- Responsiveness
- Movement
- Development, growth, & reproduction
2
Q
Who developed the cell theory and what is it?
A
Developed by Robert Hooke.
Cell theory:
1. Cell are building blocks of all plants and animals.
2. All cells come from division of pre-existing cells.
3. Cells are smallest unit that perform all vital physiological functions.
4. Each cell maintains homeostasis at the cellular level.
3
Q
Define prokaryotic cell.
A
Cells which lack a nucleus and other organelles. Ex. bacteria and archaea
4
Q
Define eukaryotic cell.
A
Cells that have membrane-bound nuclei and organelles, and can form large complex organisms (including all animals, plants, fungi). Ex. sex cells, somatic cells
5
Q
Describe the structure of a plasma membrane.
A
- Physical isolation - acts as “selective permeable barrier”
- Controls exchange with environment - ions and nutrients enter, wastes eliminated, and cellular products released
- Sensitivity to environment - extracellular fluid composition, chemical signals
- Structural support - anchors cells and tissues
6
Q
Explain the function of plasma membrane’s lipid.
A
- Main component of cell membrane as fats
- 42%
- Establishing fluidity of PL
- Passing fat soluble substances
7
Q
Explain the function of plasma membrane’s protein.
A
- Serves as pumps or channels moving materials in and out of CM
- 55%
- Integral and peripheral
- Anchoring, recognition (identifier) - MHC, enzymes, receptor and attaching to ligands, carrier proteins (glucose), channels (aquaporins for water)
8
Q
Explain the function of plasma membrane’s carbohydrate.
A
-Forms sugar and made of C, H, and O
- 3%
- Glycolipids, glycoprotein, proteoglycans
- Lubrication & protection, anchoring & locomotion, specificity in binding, recognition
9
Q
Describe the structure & function of cytoplasm.
A
Gel-like fluid in the cell which holds cytosol, membranous organelles, and non-membranous organelles (all materials in the cell and outside the nucleus).
10
Q
Describe the structure & function of cytosol.
A
- Intracellular fluid
- Dissolved materials: nutrients, ions, proteins, and waste products
- High potassium/low sodium
- High protein
- High carbohydrate/low amino
acid and fat
11
Q
Describe the structure & function of organelles.
A
- Structures with a specific function
- Non-membranous: no membrane, direct contact with cytosol, include the cytoskeleton, microvilli, centrioles, cilia, ribosomes, and proteasome.
- Membranous: covered with plasma membrane, isolated from cytosol, includes ER, Golgi apparatus, lysosomes, peroxisomes, and mitochondria
12
Q
What are 2 types of ribosomes that build polypeptides in protein synthesis?
A
- Free ribosome in cytoplasm - manufacture protein in cell
- Fixed ribosomes attached to ER - manufacture proteins for secretion
13
Q
What are proteasomes?
A
Contain enzymes (proteases) and disassemble proteins for recycling.
14
Q
What is the cytoskeleton?
A
Provides structural support for shape and strength (microfilaments, intermediate filaments, microtubules).
15
Q
What are the cancer development steps?
A
- Abnormal cells
- Primary tumor
- Metastasis
- Secondary tumor
16
Q
What is a tumor?
A
Tumor (neoplasm) is enlarged mass of cells, abnormal cell growth and division.
17
Q
What are the 2 types of tumor?
A
- Benign tumor
- Malignant tumor
17
Q
What is malignant tumor?
A
Spreads into surrounding tissues (invasion) and starts new tumors (metastasis).
18
Q
What is benign tumor?
A
Contained, not life threatening unless large.
19
Q
What is differentiation?
A
- All cells carry complete DNA instructions for all body functions.
- Cells specialize or differentiate to form tissues (liver cells, fat cells, and neurons) or by turning off all genes not needed by that cell.
- Differentiation depends on which genes are active and inactive.
20
Q
How many chromosomes in body cells?
A
46 chromosomes (23 pairs).
21
Q
What is the function of the smooth ER? And what are some example of what it synthesizes?
A
- Synthesizes lipids and carbohydrates.
- Phospholipids and cholesterol
(membranes) - Steroid hormones (reproductive
system) - Glycerides (storage in liver & fat
cells. - Glycogen (storage in muscles)
- Phospholipids and cholesterol
22
Q
What is the function of the rough ER?
A
- Active in proteins and glycoprotein synthesis
- Folds polypeptide protein structures
- Encloses products in transport vesicles
23
Q
What is the function of Golgi apparatus?
A
- Modifies and packages secretions
- Hormones or enzymes
- Released through exocytosis
- Renews or modifies the plasma membrane
- Packages special enzymes within vesicles for use in the cytoplasm
24
What is the function of the mitochondria?
- "Powerhouse of the cell"
- Produces energy in the form of ATP
- Helps in metabolic functions
- Inner membrane has "cristae" folding to increase surface area
- Has matrix which has ribosomes & DNA
25
What is the function of peroxisomes?
- Enzyme-containing vesicles that break down fatty acids and organic compounds
- Produce hydrogen peroxide (H2O2)
- Replicate by division
25
What is the function of lysosomes? What is primary and secondary lysosomes?
- Clean up inside cell: break down large molecules, attack bacteria, recycle damaged organelles, and eject wastes by exocytosis.
- Autolysis: self-destruction of damaged cells - lysosome membrane breaks down, digestive enzyme released, cell decomposes, cellular materials recycle.
- Powerful enzyme-containing vesicles
- Lyso = dissolve, Some = body
- Primary lysosomes formed by Golgi apparatus and inactive enzymes
- Secondary lysosomes are fused with damaged organelles, digestive enzyme activated, and toxic chemical isolates.
26
Describe the nucleus structure and function.
Nucleus is the cell's control center and contains:
- Nuclear envelope: double membrane around nucleus
- Perinuclear space: b/w 2 layers of the nuclear envelope
- Nuclear pores: communication passages
- Chromatin: all information to build and run organisms
- Nucleoplasm: fluid containing ions, enzymes, nucleotides, and some RNA
- Nuclear matrix: supports filaments
- Nucleoli
27
What is meant by selectively permeable membrane?
- Allows some materials to move freely
- Restricts other materials based on: size, electrical charge, molecular shape, lipid solubility
28
What are the mechanisms for transporting materials in and out of cell membrane?
1. Active (requiring energy and ATP)
2. Passive (no energy required)
29
Is diffusion active or passive transport?
Passive transport
30
Is carrier-mediated transport active or passive?
Both
31
Is vesicular transport active or passive?
Active transport
32
Describe diffusion and what factors influence diffusion.
- Net movement of molecules from area of high concentration to area of low concentration, movement down a concentration gradient.
- Factors influencing: distance the particle has to move, size (smaller = faster), temperature (hotter= faster), [] gradient, and electrical forces.
33
Describe osmosis.
- Movement of water from an area of low solute concentration to high solute concentration.
- Hydrostatic pressure!!
34
Define isotonic, hypotonic, and hypertonic, and determine the effect each would have on red blood cells.
- Isotonic solution (normal) = normal RBC b/c same solute [] inside and outside cell.
- Hypotonic solution (diluted) = swollen RBC b/c higher solute [] inside cell
- Hypertonic solution (concentrated) = shrunken/crenated RBC b/c lower solute [] inside cell
35
Describe the driving force for water movement across plasma membrane.
- Water moves across PM by simple or channel-mediated diffusion:
- Simple diffusion: lipid-soluble compounds (alcohol, fatty acids, and steroids) and dissolved gases (O2 & CO2).
- Channel-mediated diffusion: water-soluble compounds and ions, and factors in channel-mediated diffusion are size, charge, interaction with the channel - leak channels.
36
Describe facilitated diffusion (passive).
- Carrier proteins transport molecules too large to fit through channel proteins (glucose, amino acids)
- Molecules binds to receptor site on carrier protein
- Protein changes shape, molecules pass through
- Receptor site is specific to certain molecules
37
Describe carrier-mediated transport.
For ions and organic substances,
- Characteristics:
- Specificity: one transport protein, one set of substances
- Saturation limits: rate depends on transport proteins, not substrate
- Regulation: cofactors such as hormones
38
What is cotransport?
2 substances move in the same direction at the same time.
39
What is countertransport?
One substance moves in while another moves out.
40
Describe active transport.
- Active transport moves molecules against a concentration gradient, using energy (ATP) from area of low concentration to area of high concentration
- Ion pumps move ions (Na+, K+, Ca2+, Mg2+)
- Exchange pump countertransports 2 ions at the same time
- Sodium-potassium pump, active transport, carrier-mediated
- Na+ out, K+ in
- 1 ATP moves 3 Na+ out, and 2 K+ in
41
Describe endocytosis.
Bulk material can enter by getting enclosed into a vesicle of the plasma membrane, which then pinches off into the cell.
42
Describe exocytosis.
Unwanted materials accumulate into a vesicle, attach to the plasma membrane and get released out.
43
Discuss transmembrane potential.
- Charges are seperated creating a potential difference.
- Unequal charge across the plasma membrane is transmembrane potential.
- Resting potential ranges from -10mV to -100mV, depending on cell type.
44
What is the cell cycle steps in order?
1. Interphase
2. Prophase
3. Metaphase
4. Anaphase
5. Telophase and Cytokinesis
45
Describe the term tissues and the importance of this structure.
- Tissue is a collection of cells + cell's products/extracellular matrix (ECM) that perform a specific function.
- By joining various tissues, organs develop.
- Tissues are distinct structure that form organs.
46
What are 4 major types of tissues in the body and describe their roles?
1. Epithelial
- Physical protection, control permeability, sensation, and secretion.
- Criteria:
- Cellularity: Almost made by cells
- Polarity: Having distinct surfaces:
Apical, Basal, Lateral, Basolateral
- Attachment: From basal surface
to Basal Lamina or Basement
Membrane
- Avascularity: nutrition by
diffusion or absorption from
surfaces
- Regeneration: High rate of cell
turnover
- Types:
- Ordinary (Regular)
- Glandular
2. Connective: fat and other soft padding tissue, bone, tendon
3. Muscular: cardiac muscle, smooth muscle, skeletal muscle
4. Nervous: brain, spinal cord, nerves
47
Name and briefly describe the different categories of epithelial tissues based on cell shape and number of cell layers found in tissue.
- Ordinary Epithelia (covering, lining, sensory, myoepithelial)
- Simple (one layer): squamous,
cuboidal, columnar
- Stratified (multiple layers):
squamous, cuboidal, columnar
pseudostratified, transitional
- Glandular Epithelia
- Exocrine:
merocrine/apocrine/holocrine
- Endocrine:
paracrine/autocrine/endocrine
48
What are the specialization of epithelial cells?
Microvillus:
- Finger-like projections
- Only found on apical surfaces
- 1 micrometer in length
Cilium (cilia)
- Only found on apical surfaces
- Motile (respiratory ducts)
- Non-motile (primary or sterocilia), single and sensory function
49
Compare the structures and functions of various types of connective tissues.
- Connective tissues are the most abundant tissues in our body.
- Made up of:
- Specialized cells + ECM
- ECM = fibers + ground
substances
- Function:
- Establishing a structural framework for the body
- Transporting fluids and dissolved materials
- Protecting delicate organs
- Supporting, surrounding, and interconnecting other types of tissue
- Storing energy reserves, especially in the form of triglycerides
- Defending the body from invading microorganisms
50
What are the 3 types of fibers commonly found in connective tissues?
1. Collagen fiber
2. Elastic fiber
3. Reticular fiber
51
What are the 6 types of cells commonly found in connective tissues?
1. Fibroblasts
2. Mast cells
3. Plasma cells
4. Macrophages
5. Adipocytes
6. Leukocytes
52
Discuss the fluid in connective tissue.
Blood and lymph
- Watery matrix of dissolved proteins
- Carry specific cell types (formed elements): formed elements of blood
- Red blood cells (erythrocytes)
- White blood cells (leukocytes)
- Platelets
53
What are the fluid elements of connective tissues extracellular?
-Plasma
-Interstitial fluid
-Lymph
- Collected from interstitial space
- Monitored by immune system
- Transported by lymphatic (lymphoid) system
- Returned to venous system
54
Compare the criteria of cartilage and bone tissues.
- Cartilage: connective tissue with very firm extracellular matrix
- Supports soft tissues (nose, ear, trachea)
- Shock absorption and friction reduction in joints
- Development and growth of long bones
- Without vessel, lymph, and nerves
- Bone: connective tissue with calcified matrix
- Support (skeleton, skull, vertebral column)
- Movement (leaver system)
- Hematopoiesis
- Storage of calcium
- Highly vascularized
55
Name different types of muscular tissue and where they are found.
1. Skeletal (straited): long, cylindrical multinucleated cells with cross-striations, peripheral nuclei, quick & forceful contraction; voluntary control.
2. Cardiac: cross-striations, nucleus central, elongates and branched cells joined by intercalated disks; involuntary, rhythmic, and forceful.
3. Smooth (visceral): fusiform cells, central nucleus, no striations, slow contractions, involuntary.
56
Name two categories of nervous tissue.
CNS & PNS:
- Function: coordination of body activities
- Composed of:
- Neurons
- Neuroglia(Glial Tissue)
