Cells, Tisues And Homeostasis Flashcards
Describe the function of the plasma membrane
Control the passage of substances in and out of the cell, regulating the intracellular environment
Describe the structure of the plasma membrane
Two layers of phospholipids with proteins and sugars embedd within it
Lipid cholesterol is present
Phospholipid head is hydrophilic and the fatty acid tail is hydrophobic
Describe diffusion
Movement of molecules from an area of high concentration to an area of low concentration
Describe osmosis
Passive movement of water down its concentration gradient to reach equilibrium
Describe facilitated diffusion
Passive process of movement with molecules which cannot diffuse across the semipermeable membrane unaided, e.g. glucose
Describe active transport
Active process of the movement of substances In against its concentration gradient using ATP aided by a carrier protein
Describe the function of the nucleus
Directs the cell’s metabolic activity and contains the body’s genetic information (DNA)
Describe chromatin
A fine network of threads which forms chromosomes when cell division is occurs
Describe the nucleolus
Involved in the production of the components of ribosomes
Describe the function of mitochondria
Synthesise ATP
Describe the function of ribosomes
Synthesise proteins from amino acids using mRNA as the template
Describe the function of the Endoplasmic reticulum
Smooth: synthesises lipids and steroid hormones
Rough: site of protein synthesis for extra cellular
Describe the function of the Golgi apparatus
Packages proteins into vesicles for exocytosis
Describe the function of lysosomes
Small vesicles, Contain a variety of enzymes used to breakdown fragments of organelles and large molecules e.g. RNA, DNA, carbs to be either exported as cell waste or recycled can digest foreign material
Define organelles
Small organs with highly specialised functions usually enclosed by their own membrane with in the cytoplasm
Define a tissue
Consist of large numbers if the same cell type, four types: epithelial or epithelium, connective, muscle and nervous
Describe the structure of epithelial tissue
Cells lining body cavities, e.g. gut lining, glands
Simple, squamous and cuboidal and columnar and stratified
Describe the function of epithelial cells
Secretion, absorption and protection of underlying structures e,g, from chemicals damage
Describe the function of connective tissue
Binding, structural support, protection, insulation and transport
Describe the function of skeletal muscle tissue
Skeletal: under voluntary control attached to bones for motion
Describe the function of smooth muscle tissue
Under involuntary control and initiates its own contraction and forms walls of tubes, e.g. airways, blood vessels, gut, bladder
Describe function of cardiac muscle
Found in heart wall, under involuntary control, contracts to cause heart to pump
Describe the function of nervous tissue
Excitable cells- neurones, initiates, receive , conduct and transmit info
Non-excitable cells- glial cells support neurones
Describe an organ
The grouping of two or more tissue types into a structure performing the same function
