organization, homeostasis and the cell

Cytoplasm

Contents between plasma membrane and nucleus

Cytosol

Fluid-like, organelles imbedded throughout

Cytoskeleton

Framework of protein fibres beneath plasma membrane

Microfilament

Small protein, internal structure

Intermediate fiber

Medial protein, rods to support and stabilize

Microtubule

Big protein, helps with movement of organelles and vesicles

Cilia

Short hair-like tentacles on outside of cell. Moves fluid along cell surface

Flagella

Longest hair-like tentacle on outside of cell. Moves cell

Ribosomes

Site of protein synthesis

Endoplasmic reticulum

Rough ER: have ribosomes, synthesize proteins

Smooth ER: no ribosomes, synthesize fatty acids

Golgi apparatus

Packs proteins for transport

Mitochondria

Generates ATP

Lysosome

Contains digestive enzymes

Peroxisome

Detoxifies toxic substances

Proteasome

Break down proteins

Transcription

Occurs in nucleus, converts DNA to MRNA

Translation

Occurs in cytoplasm, converts MRNA to protein

Homeostasis

The ability of an organism to maintain a consistent internal environment in response to changing control systems

Challenges for homeostasis

Physical insults, changes in internal environment, physiological stress

What is a receptor, example.

Structure that detects stimulus, temperature sensors in skin and hypothalamus

What is a control centre, example

Integrates information and initiates change through effector. Thermoregulatory centre in brain

What is an effector, example

Structure that brings change to stimulus, sweat glands in skin increase secretion of blood vessels in skin

2 types of homeostatic control systems

Negative feedback

Positive feedback

Negative feedback

Counteracts a change in a controlled condition. example: temperature regulation

Positive feedback

Strengthens a change in one of the body’s controlled conditions. Example: breast feeding