Cells And Tissues Flashcards
Chemical elements and atoms
- All forms of matter are made up of a limited number of building blocks called chemical elements
- Substances cannot be broken down onto similar form
What are enzymes ?
Molecules usually contain proteins that speed up chemical reactions and cellular controls
Structure and function of DNA
- Double helix and is the primary chemical in genes
- RNA differs in structures and chemical composition from DNA
- Function is to carry out the instructions encoded in DNA for protein synthesis
ATP
1.energy transferring energy
2. When it transfers ATP is decomposed by hydrolysis to ADP and P
3. ATP is synthesised from ADP and pushes energy supply by the breakdown of glucose
Regions of a cell
- Nucleus
- Cytoplasm
- Plasma
Diffusion
- The selective permeability of the plasma membrane supports the existence of concentration gradients
- Differences in the concentration of chemicals between one side of the membrane and the other
- Movement of substances due to the kinetic energy
- (In net Diffusion substances move from an area of high to low concentration until equilibrium is released)
- (In simple diffusion lipid soluble substances move through the lipid bilayer)
- (In facilitated diffusion substances cross the membrane with the assistance of ion chemicals and carriers)
Osmosis
- (Movement of water molecules through a selectively permeable membrane from a high to low water concentration)
- In an isotonic solution red blood cells maintain normal shape
- In an hypotonic solution they gain water and undergo hydrolysis
- In a hypertonic solution they loose water and undergo crenation
Active transport
Transport in which cell expends energy to move a substance across the membrane against its concentration gradient aided by membrane proteins that act as pumps
Transport in vesicles
Movement of substances in or out of a cell wall in vesicles that start from the plasma membrane
What is Endocytosis ?
Movement of substances into a cell in vesicles
What is exocytosis ?
Movement of substances out of a cell in secretory vesicles
Cytoplasm - consists and includes
- Consists of cytosol and organelles
- Includes all cellular contents between the plasma membrane and nucleus
- Organelles are specialised cellular structures with characteristics shapes and functions
Cytoskeleton - network and provide
- Network of several kinds of protein filaments
- Provide a structural framework for the cell and generate movement
Components of the cytoskeleton
- Microfilaments
- Intermediate filaments
- Microtubules
Ribosomes - composed and consists
- Composed of ribosomal RNA and ribosomal proteins
- Consists of two sub units and site of protein synthesis
Endoplasmic reticulum - network and ribosomes
- Network of membranes that extend from the nuclear envelope through the cytoplasm
- Rough ER is studded with ribosomes
- Proteins synthesised on the ribosomes enter the ER for processing and sorting
- Where glycoproteins and phospholipids form
Smooth endoplasmic reticulum - ribosomes
- Lacks ribosomes
- Site where fatty acids and steroids are synthesised
- Participates in releasing glucose from the liver to the bloodstream inactivating and detoxifying drugs, ect
- Storing and releasing calcium ions that trigger contraction in cells
Golgi apparatus - consists
- Consists of flattened sacs called cisterns that receive proteins synthesised in the rough ER
- Within the Golgi cisterns the proteins are modified, stored and packaged into vesicles for transport to different destinations
- Small processed proteins leave the cell in the secretory vesicles and some are incorporated into the plasma membrane and some enter lysosomes
Mitochondria - consists and produce
- Consists of smooth outer membrane and inner membrane Containing folds called mitochondria and a fluid filled cavity called the matrix
- Produce most of the cells ATP
Lysosomes - function and what it is
- Membrane enclosed vesicles that contain digestive enzymes
- Function in digestion of work out organelles and own cells
Peroxisomes
- Similar to lysosomes but smaller
- Oxidise various organic substances
Proteosomes
Contain proteases that continually degrade unneeded, damaged or faulty proteins
Nucleus
- Consists of a double nuclear envelope and pores which control the movement of substances between the nucleus and cytoplasm
- The nucleoli produces ribosomes and genes arranged on chromosomes
- Most body cells have a single nucleus
- Genes control cellular structure and functions
Translation
- Process in which the mRNA associates with ribosomes and directs synthesis of a protein converting the nucleotide sequence in the mRNA into a specific sequence of amino acids across the protein
- MRNA binds to a ribosome specific amino acid which attaches to a transfer RNA and anticodons of tRNA bind to codons of mRNA bringing specific amino acids into position on a growing protein
- Begins at the start codon and terminates a the stop codon
Cell division
- Process by which cells reproduce themselves
- Cell division that results in an increase in the number of body cells is called somatic cell division which involves a nucleoli division called mitosis plus division of the cytoplasm called cytokinesis
- Cell division that results in the production of sperm and oocytes is called reproductive cell division
Cell cycle
- Orderly sequence of events in which a cell duplicates its contents and divides into 2 and consists of interphase and mitotic phase
- Replication and distribution of 2 sets of chromosomes into sequence nuclei and consists of prophase, metaphase, anaphase and telophase
- During cytokinesis which usually begins late in anaphase and ends in telophase a cleavage furrow forms and progresses inwards cutting thorough the cel to form 2 separate identical cells each with equal portions of cytoplasm, organelles and chromosomes
Interphase
- The DNA molecule or chromosomes replicate themselves sp that identical chrosmomes can be passed onto new cells
- A cell that is between divisions and is carrying on every life process is said to be in interphase
Homeostasis
- Ensures body internal environment remains constant
- A dynamic state of equilibrium
- Necessary for normal body function and life
- Homeostatic imbalance leads to disease
Sagital -
Median -
Frontal -
Transverse -
- Left and right portions
- Equal left and right portions
- Anterior and posterior parts
- Superior and inferior parts
Cranial cavity
- Formed by cranial bones
- Contains brain
Vertebral canal
- Formed by vertebral column
- Contains spina cord at the beginning of spinal nerves
Pleural cavity
- Each surround a lung
- The serous membrane of each pleural cavity is the pleura
Pericardial cavity
- Surrounds the heart
- The serous membrane of the pericardial cavity is the pericardium
Mediastinum
- Central portion of the thoracic cavity between the lungs
- Extends from sternum to vertebral column and from first rib to diaphragm
Mediastinum Contains
- Heart
- Thymus
- Oesophagus
- Trachea
- Large blood vessels
Abdominal cavity
The serous membrane of the abdominal cavity is the pericardium
Abdominal cavity contains
- Stomach
- Spleen
- Liver
- Gallbladder
- Small intestine
- Large intestine
Pleural cavity contains
- Urinary bladder
- Large intestine
- Internal organs of the reproductive system
