Nutrition & Physiology I: The Cell Quiz

Course Information

• Course title: Nutrition & Physiology I
• Course code: NFSC100
• Instructor: Margaret Slavin, PhD, RDN
• Affiliation: Associate Professor, Nutrition & Food Science, University of Maryland, College Park

Agenda

• Parts of the cell
• Cell organization into tissues and organs
• Organization into organ systems of the body

The Cell - Basic Unit of Life

• Cell components: (diagram shown)

  • Endoplasmic Reticulum (ER): involved in protein and lipid synthesis. Rough ER has ribosomes, smooth ER does not.
  • Cell Nucleus: houses genetic material (DNA).
  • Cytoplasm: fluid and organelles within the cell.
  • Peroxisome: destroys toxic materials.
  • Golgi Complex: packages proteins for export from the cell.
  • Cell (plasma) membrane: lipid bilayer, regulates transport of substances into and out of the cell.
  • Mitochondrion: main site of energy production.
  • Ribosomes: sites of protein synthesis.
  • Lysosome: digests worn-out or damaged cell components.

• Estimated number of cells in an adult human body: ~37,000,000,000,000 (Source: Bianconi et al., 2012).

Cell Types

• Diagram shows various cell types
• Examples of cell types include: Loose connective tissue with fibroblasts, bone tissue with osteocytes, Striated muscle cells, Nerve cells, Red blood cells, Intestinal epithelial cells, Smooth muscle / Fat (adipose) cells, and others

Nucleus

• Control center of the cell
• Sends instructions for growth, maturity, division, and death
• Contains DNA

Genes & Cell Function

• Genes are segments of DNA, coding for proteins.

• Proteins carry out functions in living cells.

• DNA, genes, and chromosomes are key to cell function.

• (Diagram showing DNA structure and components)

Genes - Determine Cell Function

• Each cell's nucleus contains DNA (genetic material)
• DNA coils into chromosomes
• Genes contain instructions for building proteins (via DNA templates)
• Proteins perform the work of the cells
• Cells form tissues, then organs, then organ systems, then organism

Plasma Membrane

• Structure: phospholipid bilayer with embedded proteins
• Function: regulates what enters/leaves the cell
• Proteins: various types (structural support, enzymes, receptors, transporters)
• Cholesterol: supports structure

Cytoplasm

• Fluid and organelles between nucleus and outer membrane

Mitochondria

• Powerhouse of the cell
• Produce ATP (energy)
• Have their own genetic material (separate from DNA)

Endoplasmic Reticulum (ER)

• Membranous channels involved in the synthesis, modification, and transport of cellular materials
• Closely works with Golgi apparatus and ribosomes

Ribosomes

• Process genetic instructions to create proteins (protein synthesis)
• Can be free or bound to the ER

Golgi Apparatus

• Packaging center
• Packages molecules processed by ER for transport out of the cell

Lysosomes

• Housekeeper & Recycling center of the cell
• Digests foreign bacteria, toxic substances, excess organelles, and recycles worn-out parts of the cell

Body Organization (overview)

• Cells → Tissues (epithelial, connective, muscular, nervous) → Organs → Organ systems → Organism

Integumentary System

• Skin, hair, nails, sweat glands
• Provides body covering, maintains temperature
• Excretes salts and urea
• Maintains homeostasis

Cardiovascular System

• Heart, blood vessels, blood
• Transports nutrients and oxygen around the body

Capillaries

• Enable exchange of oxygen and carbon dioxide, nutrients, and waste between blood and body tissues

Lymphatic System

• Lymph vessels, lymph nodes, spleen, and tonsils
• Returns fluids to blood
• Involved in lipid absorption
• Involved in defense against pathogens

Extracellular and Intracellular Fluids

• Plasma: fluid in the blood
• Extracellular fluid: outside cells in tissues.
• Intracellular fluid: inside cells
• Lymph: fluid that moves from bloodstream to tissue spaces then through lymphatic vessels

Skeletal & Muscular Systems

• Bones, joints, ligaments, cartilage (support and protection)
• Muscles attached to bones, internal organs, blood vessels (enable body movement)

Nervous System

• Central nervous system (brain, spinal cord): main control system
• Peripheral nervous system (nerves, nerve clusters): receive and send info to brain
• Concerned with sensation, interpretation, and integration

Endocrine System

• Hypothalamus and glands: pituitary, thyroid, adrenal, pancreas, etc
• Secretes hormones to control body activities (growth, reproduction)

Digestive & Urinary System

• Mouth, esophagus, stomach, intestines (digest and absorb food, excrete waste)
• Kidneys, bladder, ducts (excrete waste, regulate water and salt balance, regulates blood acid-base balance)

Respiratory System

• Lungs and respiratory passages (take in oxygen, get rid of carbon dioxide and other wastes)
• Nutrients affect ability to carry oxygen and protection mechanisms

Reproductive System

• Gonads, genitals (concerned with production of offspring)
• Certain nutrients are required for proper development and function

Immune System

• Nonspecific & Specific defense
• Main immune cells: lymphocytes & phagocytes
• Produce antibodies, destroy invaders, clean up debris, resist diseases
• Nutritional status is important

Conclusions

• For optimal health, each body system must develop and function correctly
• Systems work together for life
• Diet/nutrition can affect body systems