Lecture 2 (1/20) - Cellular Biology Review

Phospholipids

Hydrophilic head

Hydrophobic tail

The Body Cavities

Cranial

Pleural + Pericardial= Thoracic

Diaphragm

Abdominal+ Pelvic= Abdominopelvic

Pericardial sac

tissue that surrounds the heart

How can phospholipids arrange themselves?

Bilayers

Micelles

Liposomes

Bilayer

forms a sheet

Micelles

droplets of phospholipids

Liposomes

have an aqueous center

Fluid Mosaic Model

describes the plasma membrane as a highly flexible, two-dimensional liquid (fluid) composed of a phospholipid bilayer with embedded proteins, cholesterol, and carbohydrates arranged in a constantly shifting pattern (mosaic)

Cell Membrane Components

Cell Membrane consists of…

Cholesterol, Phospholipids, Carbohydrates, and proteins

Cholesterol + Phospholipids

Lipid bilayer- selective barrier between cytosol and external environment

Phospholipids + carbohydrates

Glycolipids

Carbohydrates + Proteins

Glycoproteins

Glycolipids + Glycoproteins

Structural stability

Cell Recognition

Immune Response

Cell Strcuture

Nucleus

Cytoplasm

Cell Membrane

Cytoplasm Components

Cytosol

Membrane Organelles

Inclusions

Protein fibers

Membrane organelles

Mitochondria

Endoplasmic Reticulum

Golgi Apparatus

Lysosomes

Peroxisomes

Inclusions

Lipid droplets

Glycogen granules

Ribosomes

Protein fibers

Cytoskeleton

Centrioles

Cilia

Flagella

Microvilli

Increase cell surface area

Microfilaments

form a network just inside the cell membrane

Microtubules

the largest cytoskeleton fiber

Intermediate fialments

myosin and keratin

Peroxisomes

contain enzymes that break down fatty acids and some foreign materials

Lysosomes

small spherical storage vesicles that contain powerful digestive ensymes

Centrioles

are made from microtubules and direct DNA movement during cell division

Mitochondira

ATP production

Golgi Apparatus and Vesicles

participates in protein modification and packaging.

Endoplasmic Reticulum

is a network of interconnected membrane tubes that are a continuation of the outer nuclear membrane.

Rough Endoplasmic Reticulum

main site of protein synthesis

Smooth Endoplasmic Reticulum

synthesizes lipids and, in some cells, concentrates and stores calcium ions.

Protein Synthesis: Step 1

mRNA is transcribed from genes in the DNA

Protein Synthesis: Step 2

mRNA leaves the nucleus and attaches to cytosolic ribosomes, initiating protein synthesis.

Protein Synthesis: Step 3

Some proteins are released by free ribosomes into the cytosol or are targeted to specific organelles.

Protein Synthesis: Step 4

Ribosomes attached to the rough endoplasmic reticulum direct proteins destined for packaging into the lumen of the rough endoplasmic reticulum.

Protein Synthesis: Step 5

Proteins are modified as they pass through the lumen of the ER

Protein Synthesis: Step 6

Transport vesicles move the proteins from the ER to the Golgi Apparatus

Protein Synthesis: Step 7

Golgi cisternae migrate towards the cell membrane.

Protein Synthesis: Step 8

Some vesicles bud off the cisternae and move in a retrograde or backward fashion

Protein Synthesis: Step 9

Some vesicles bud oof to form lysosomes or storage vesicles

Protein Synthesis: Step 10

Other vesicles become secretory vesicles that release their contents outside the cell.

Cell Junctions

Connect one cell with another cell with membrane spanning proteins.

Gap junctions

communicating

Tight junctions

occluding

Desmosome

Cell-to-cell anchoring junction

Cell Junctions

Epithelial tissue

body tissue that covers all internal and external body surface, lines cavities and hollow organs, and form glands.

Exchange epithelium

these thin, flat cells allow movement through and between the cells.

Transporting Epithelium

selectively move substances between a lumen and the ECF

Ciliated Epithelium

Beating cilia create fluid currents

Protective Epithelium

stacked layers of cells that are constantly being replace.

Secretory

make and release a product.

Exocrine Glands

organs that produce and secrete substances directly into an epithelial surface via a duct.

Endocrine Glands

ductless organs of the endocrine system that synthesize and secrete hormones directly into the bloodstream.

Loose Connective Tissues

very flexible with multiple cell types and fibers.

Bone and Cartilage

forms when osteoblasts deposit calcium phosphate crystals in the matrix.

firm but flexible matrix secreted by cells called chondrocytes

Dense Regular Connective Tissue

collagen fibers of tendon are densly packed into parallel bundles.

Blood

consists of plasma plus red and white blood cells and the cell fragments called platelets

Adipose tissue

in white fat, the cell cytoplasm is almost entirely filled with lipid droplets.

Hair follicles

secrete the nonliving keratin shaft of hair

Sebaceous gland

exocrine glands that secrete a lipid mixture

Arrector pili muscles

pull hair follicles into a vertical positions when the muscles contracts (goose bumps)

Sweat gland

secrete a dilute salt fluid to cool the body

Empidermis

consists of multiple cell layers that create a protective barrier

Dermis

Loose connective tissue that contains exocrine glands, blood vessels, muscles, and nerve endings.

Hypodermis

contains adipose tissue for insulation

Apocrine glands

release waxy or viscous milky secretions in response to fear or sexual excitement.

Hemidesmosomes

tie epidermal cells to fibers of the basal lamina

Basal lamina

an acellular layer between epidermis and dermis