Module 3 - Cells Flashcards
3 principle parts of cell
Plasma Membrane
Cytoplasm
Nucleus
Plasma Membrane
Flexible, sturdy barrier
Contains cytoplasm
Fluid mosaic model
Double layer (bilayer) of phospholipid molecules
Proteins dispersed throughout
Surface hydrophilic (loves water) – polar phosphate heads
Internal hydrophobic – nonpolar fatty acids
Integral proteins – firmly inserted – glycoproteins – serve as channels, transporters, and receptors, and enzymes
Peripheral proteins – loosely on inner and outer surface – serving as enzymes or cytoskeletal anchors
Cholesterol – stabilizes and reduces fluidity
Selectively permeable
Yes – small, nonpolar, uncharged molecules
No – ions, charged, or polar molecules
Transmembrane protein act as channels
Macromolecule use vesicular transport
Integral Proteins
Integral proteins – firmly inserted – glycoproteins – serve as channels, transporters, and receptors, and enzymes
Peripheral proteins
Peripheral proteins – loosely on inner and outer surface – serving as enzymes or cytoskeletal anchors
Cholesterol
Cholesterol – stabilizes and reduces fluidity
Parts of Cytoplasm
Cytosol
Cytoskeleton
Organelles
Cytosol
Cytosol – intracellular fluid
semi fluid – contains inclusions and dissolves solutes
mostly water, proteins, carbs, lipids, and inorganic substances
chemicals either in solution or colloidal (suspended) form
medium where metabolic reactions occur
Cytoskeleton
Microfilaments
Intermediate Filaments
Microtubules
Centrosomes
Cilia and Flagella
Microfilaments
Microfilaments – made of actin – function in movement and mechanical support
Intermediate filaments
Intermediate filaments – diff proteins – function to support and anchor organelles
Microtubules
Microtubules – protein called tubulin – determines cells shape – transports organelles – moves chromosomes during division
Centrosomes
Centrosomes – dense areas of cytoplasm containing centrioles – centers for organizing microtubules interphase and mitotic spindle during division
Cilia and Flagella
Cilia and Flagella – hair like projections from surface – move materials. Flagella – sperms
Ribosomes
Ribosomes or Synthesizer – consist of ribosomal RNA and ribosomal proteins – freely or in ER – synthesize proteins by building amino acids
Endoplasmic Reticulum
Endoplasmic Reticulum - STORAGE – network of membranes in flattened sacs (cisterns) – holds ribosomes and newly synthesized proteins – transports and stores – releases calcium for muscle contractions
Rough ER
Rough ER – continuous with nucleus – outer surface studded with ribosomes – synthesizes glycoproteins and fats
Smooth ER
Smooth ER – Extends from rough – network of tubules – no ribosomes on membrane – detoxes chemicals
Golgi Complex
Golgi Complex or SORTER – packages, processes, and delivers proteins sends to other places in cell – improves and fixes proteins from ER – forms vesicles to move molecules to membrane, exocytosis – tags things for location – Membrane, lysosomes, and secretory vesicles
Lysosomes
Lysosomes or Garbage Guts – cut or digest – membrane bound – digests molecules – formed in golgi complex – intracellular digestion – autophagy – worn out organelles – engulf structures – material can be reused
Peroxisomes
Peroxisomes – smaller than lysos – contain enzymes that oxidizes organic substances - lipid metabolism and catabolism of D-amino acids, polyamines and bile acids
Proteasome
Proteasome – tiny membrane bound sac that holds protease enzyme – cuts proteins
Mitochondrion
Mitochondrion – double membrane bound – outer is smooth – inner has folds (cristae) – site of ATP productions by catabolism of nutrient molecules – aerobic cellular reaction – self replicating – own DNA
Nucleus
Nucleus
Covered by nuclear envelope
Pores – nucleoli
Genetic material (DNA) arranged in single file along chromosomes
DNA is coiled with proteins
26 chromosomes in 23 pairs
Instructions for protein synthesis in DNA
Transcription
Transcription – a section of DNA is copied onto strand of RNA – mRNA (messenger) – makes a template – directs protein synthesis – RNA polymerase comes to the section and opens it, elongation – the mRNA will leave the nucleus to find a ribosome - DNA synthesizes rRNA (ribosomal) and tRNA (transfer)
Translation
Translation – inside ribosome - mRNA acts as a code for specific protein – the template will code for its anticodon – carried by tRNA – initiator tRNA will line up with mRNA starter codons and begin bringing amino acids to grow the polypeptide chain with matching anti codons – mRNA is translated into protein that will dictate all actions and representations of genes
Cell Division
Cell Division
Process of cell reproduction
Mitosis, meiosis, and cytoplasmic division (cytokinesis)
Mitosis
Mitosis – increase body cells – nuclear division, with cytokinesis
Distribution of two sets of chromosomes, one set for each nuclei
Meiosis
Meiosis – production of sperm and eggs
interphase
Normal cell life – interphase
Mitotic phases
Mitotic phases – Prophase, metaphase, anaphase, telophase, cytokinesis - PMAT
Prophase
Prophase:
chromosomes condense in nucleus and become visible – become sister chromatids
spindle fibers emerge from centrosomes
nuclear envelope breaks down
centrosomes move towards opposite poles
Metaphase
Metaphase:
Centrosomes line up in middle – metaphase plate
Each sister chromatid is attached to spindle fiber
Anaphase
Anaphase:
Centrosomes split
Sister chromatids are split and dragged to opposite sides
Telophase
Telophase - Chromosomes go to opposite sides and begin decondensing
Nuclear envelope begins to form around chromosomes
Spindle pull nuclei to opposite ends
Cytokinesis
Cytokinesis:
A cleavage furrow forms and separates nuclei
Active or passive Transport - cell movement
Transport
Solutes = substances dissolved in a solvent
Concentration gradient is difference concentrations of a substance b/w two areas
Vesicular Transport
Vesicular:
Formation of membrane surrounded vesicles to move materials in or out of cell
Endocytosis
Endocytosis – particle too large to enter cell
Phagocytosis
Phagocytosis – large particles
Pinocytosis
Pinocytosis – fluid with solutes
Receptor-mediated
Receptor-mediated
Exocytosis
Exocytosis – membrane encloses structure in cell and beings to surface for exit
Passive Transport
Passive Transport
Non-mediated
Mediated
Diffusion
Osmosis
Passive transport: Non-mediated
Non-mediated – diffusion through lipid bilayer or through channel
Passive transport- mediated
Mediated – facilitated diffusion
Solute binds to transporter
Conformational change
Enters cell
Diffusion
Diffusion – random mixing of particles in a solution
Steepness of concentration gradient
Temperature
Size or mass of substance
Surface area
Diffusion distance
Osmosis
Osmosis – diffusion of water thru a membrane
Movement of water (solute) from high concentration to low
Osmosis - Tonicity of solution
Tonicity of solution – concentration in and out
Osmosis - Isotonic
Isotonic – same in and out
Osmosis - Hypotonic
Hypotonic – solutes outside less – solutes inside more – swell
Osmosis - Hypertonic
Hypertonic – solutes outside more – solutes inside less – shrink
Active Transport
Active Transport – energy needed to move solute against gradient
Ions. Amino acids, and monosaccharides
Pumps substances
ATP
Changes shape of transporter protein
