Week 1 - Lecture 2a - A review on cellular structure and function Flashcards
Chemical level
Atoms combine to form molecules
cellular level
cells are made up of molecules
Tissue level
tissues consist of similar types of cells
Organ level
organs are made up of different types of tissues
Organ system level
organ system level consists of different organs that work together closely
Organism level
the human organism is made up of many organ systems
Integumentary system
separates the internal environment from the external environment
Nervous system
Major regulatory system of the internal environment; senses change, integrates and sends signals to effections (muscular organs, glands)
Digestive system
breaks down nutrients from the external environment and absorbs them into the internal environment
Respiratory system
exchanges O2 and CO2 between the internal and external environment
Endocrine system
Regulates internal environment by secreting hormones that travel through the bloodstream to target areas
Circulatory system
transports nutrients, water, oxygen, hormones, wastes and other materials within the internal environment
Skeletal system
supports, protects and moves body, also stores minerals
Muscular system
powers and directs skeletal movements
Reproductive system
produces sex cells that form offspring, ensuring survival of genes. Females system is also site of fertilisation and early development
Immune system
defends internal environment against injury from foreign cells and other irritants
Lymphatic system
Drains excess fluid from tissues, cleans it and returns it to the blood
Urinary system
adjusts internal environment by excreting excess water, salt and other substances
review
cell structure slide 5
Plasma membrane composition and function
C: lipid bilayer containing phospholipids, steroid, proteins and carbohydrates
F: isolation, protection, sensitivity, support; controls entry and exit of materials
Cytosol Composition and function
C: fluid component of cytoplasm
F: distributes materials by diffusion
Cyto skeleton (Microtubule/Microfilaments) Composition and function
C: proteins organised in fine filaments or slender tubes
F: Strength and support, movement of cellular structures and materials
Microvilli composition and function
C: membranes extensions containing microfilaments
F: increase surface area to facilitate absorption of extracellular materials
Centrosome (centrioles) composition and function
C: cytoplasm containing two centrioles at right angles, each centriole at right angles each centriole is composed of 9 microtubule triplets in a 9 + 0 array
F: essential for movement chromosomes during cell division ; organisation of microtubules in cytoskeleton
Cilia composition and function
C: membrane extensions containing microtubule doublets in a 9+2 array
F: movement of material over cell surface
Ribosomes Composition and function
C: RNA +proteins, fixed ribosomes bound to rough endoplasmic reticulum, free ribosomes scattered in cytoplasm
F: protein synthesis
Proteasome composition and function
C: hollow cylinders of proteolytic enzymes with regulatory proteins at ends
F: breakdown and recycling of damaged or abnormal intracellular proteins
Mitochondria composition and function
C: double membrane, with inner membrane fold (cristae) enclosing important metabolic enzymes
F: produces 95% of the ATP required by the cell
Endoplasmic Reticulum composition and function
C: networks of membranous channels, extending throughout the cytoplasm
F: synthesis of secretory products; intracellular storage and transport
Rough ER composition and function
C: has ribosomes bound to membranes
F: modification and packaging of newly synthesised proteins
Smooth ER composition and function
C: lacks attached processes
F: lipid and carbohydrate synthesis
Golgi apparatus composition and function
C:stacks of flattened membranes (cristenae) containing chambers
F: storage, alteration and packaging of secretary products and lysosomal enzymes
Lysosomes composition and function
C:Vesicles containing digestive enzymes
F: intracellular removal of damaged organelles of pathogens
Peroxisome composition and function
C: vesicle containing degradative enzymes
F: catabolism of fats and other organic compounds; neutralisation of toxic compounds generated in the process
Nucleus composition and function
C: nucleoplasm containing nucleotides , enzymes nucleoproteins and chromatin; surrounded by double membrane (nuclear envelope)
F: control of metabolism; storage and processing of genetic information; control of protein synthesis
Nucleolus composition and function
C: dense region in the nucleoplasm containing DNA and RNA
F: site of RNA synthesis and assembly of ribosomal subunits
What is cell diffusion
cell travel from an area of higher concentration to an area of low concentration
what is simple diffusion
the process of a substance moving through a membrane without the use of an intermediary such as an integral membrane protein
What is endocytosis
the taking in of a matter by a living cell by investigation of its membrane to form a vacuole
‘into cell’
What is exocytosis
a process by which the contents of a cell vacuole are released to the exterior through fusion of the vacuole membrane with the cell membrane
‘out of cell’
what is pinocytosis
the ingestion of liquid into a cell by the budding of small vesicles from the cell membrane
fluid phase endocytosis
What is phagocytosis
engulfing of foreign solids by phagocytic cells
- releasing oxygen free radicals
What is receptor mediated endocytosis
engulfed particles attach to receptors before endocytosis occurs (enzymes, insulin, flu virus, diphtheria, cholera toxin
Secretion via exocytosis
cellular products packaged into vesicles
transport out of the cell by exocytosis
Respiration
we can use glucose to produce energy
-oxygen helps get the most out of it
in the absence of oxygen, we can only use glycolysis and make a few ATP
- with oxygen can make a lot of ATP
2: 32 ATP
Communication
proteins are important for cell function
- genes control production in response to cellular need
Feedback mechanisms regulate gene activation
- control productions of proteins
- prevent cellular damage by overproduction of under production
Reproduction
cellular division under genetic control
cellular proliferation increases cell numbers
cellular differentiation directs the development of specific cell types
- all cells contain identical genetic material
- differentiation explains how a cell develops one type of tissue, another develops to another
most of a cell’s life is spent in the non-dividing state (interphase)
Meiosis
cell division producing gametes (sex cells, half of the chromosomes)
Mitotic cell division
produces clones ( I reproduce myself)
- essential for the body growth and tissue repair
- occurs continuously in some cells
- skin : intestinal lining : immune cells (during infection)
- Less frequently
- -liver cells, maintain organ size
- none in most mature cells of nervous tissue, skeletal muscle and cardiac muscle
- -repairs with fibrous tissue
