Human Physiology Chapter 2 Cell Structure & Function Flashcards
what are biomolecules?
- molecules made by living things
- contain carbon
What are the 4 basic types of biomolecules?
- Carbohydrates
- Lipids
- Amino acids and proteins
- Nucleotides
what are carbohydrates composed of?
- carbon
- hydrogen
- oxygen
- the general formula: Cn(H2O)n = (CH2O)n
What are the 3 types of carbohydrates?
- Monosaccharides
- Disaccharides
- Polysaccharides
how many cells are in the body?
100 trillion
what are all cells derived from?
- fertilized ovum
how many types of cells are there?
- 200
- 4 general categories
what is a plasma membrane?
- Barrier between cell and external environment
- Fluid inside cell = intracellular fluid (ICF)
- Fluid outside cell = extracellular fluid (ECF)
what are the internal components of a cell?
- Nucleus
- Cytoplasm
- Cytosol
- Organelles
what does the structure of the plasma membrane consist of?
The fluid mosaic model:
- Phospholipid bilayer
* Cholesterol
* Membrane proteins
* Membrane carbohydrates
what is a phospholipid to a cell?
- basic structure of a membrane
- barrier to passage of water-soluble substances between ICF and ECF
- Provide fluidity to the membrane, especially within
a layer
are phospholipids impermeable to water?
- yes
- doesn’t allow water in
what are the functions of a phospholipid?
- Barrier to passage of water-soluble substances between ICF and ECF
- Provide fluidity to the membrane, especially within a layer
define aquaporins?
- allow water through
- integral membrane proteins
what is the function of cholesterol in the cell?
- adds fluidity to the cell membrane
- Interferes with hydrophobic interactions between phospholipids
- Prevents crystallization of phospholipids - decrease permeability of the membrane to water
define amphipathic.
- having both hydrophilic and hydrophobic parts
how do you isolate proteins
- the membrane must be disrupted
what are transmembrane proteins?
- channels
- carrier proteins
what is the function of a membrane carbohydrates?
- covalently bound to membrane lipids or proteins
- help with cell recognition
ex: glycoproteins, glycolipids
what is the structure of the nucleus?
- Nuclear envelope
- Nuclear pores
- Nucleolus: Site of ribosomal RNA (rRNA) synthesis
what is the function of the nucleus?
- transmission and expression of generic info
- contains DNA: stores genetic code
- transcribes DNA to RNA: which is necessary to express the genetic code
what is cytosol?
- fluid of the cell
what is the function of the cytosol?
- location of specific chemical reactions
- storage of fat and carbs
- storage of secretory vesicles
what are organelles?
- specialized structures that perform various jobs inside cells
what is the function of organelles?
- membrane separates the structure from the cytosol
what is a endoplasmic reticulum (ER)
- a network of membranous tubules within the cytoplasm of a eukaryotic cell, continuous with the nuclear membrane. It usually has ribosomes attached and is involved in protein and lipid synthesis.
what does a rough ER look like?
- Flattened sacs
- Granular appearance due to ribosomes
what does a Smooth ER look like?
- Tubules
- Smooth appearance
- Lumens of the two ERs are continuous
where does rough ER function?
- in the synthesis of proteins to be
packaged into vesicles
where does smooth ER function?
- in lipid synthesis, including triglycerides
and steroid
-
what is the function of rough ER
-they export things out of the cell
- destined for certain organelles
what are the functions of smooth ER
- Stores calcium
- Specialized in some cells
- Example: Smooth ER in the liver contains
detoxification enzymes
what is the function of the golgi apparatus?
Post-translational processing of proteins
* Packaging of proteins (and other molecules) into vesicles and directing them to the target
what is the function of the mitochondria?
- “Power house “of the cell (generates ATP)
- Enzymes of the Krebs cycle in the matrix
- Electron transport chain on the cristae of the inner membrane
what is a lysosome?
- an organelle in the cytoplasm of eukaryotic cells containing degradative enzymes enclosed in a membrane
what are the functions of lysosomes?
- Contain enzymes that degrade cellular or extracellular debris
what two processes degrade extracellular debris
- Endocytosis
- Phagocytosis
what do peroxisomes do?
- Degrade certain waste molecules
Ie: * Amino acids
* Fatty acids
* Toxic foreign substances
what is Tay - Sachs disease?
- Genetic disorder
- Lysosomal enzymes are less effective than normal
- Buildup of specific lipids (gangliosides) results in vision
loss - Easily startled (hallmark of disease)
- Progression: Paralysis, deafness, seizures, death
- Most common in persons of Ashkenazi Jewish heritage
what are the functions of the cytoskeleton?
- Mechanical support and structure
- Intracellular transport of materials
- Suspension of organelles
- Formation of adhesions with other cells
- Contraction
- Movement
define cytoskeleton?
- Lattice of fibrous proteins on a cell
what are the filaments of a cytoskeletal?
- Microfilaments
- Intermediate filaments
- Microtubules
what are the functions of microfilaments?
- Muscle contraction
- Amoeboid-like movements
- Separation of cytoplasm during cell division
- Structural support for cell projections
- Microvilli
- Hair cells (specialized microvilli)
made of actin
what are the common types of intermediate filaments?
- Myosin
- Keratin
- 10 nm in diameter
what are the functions of microtubules?
Mitotic spindle
* Major component of cilia and flagella
* Cilia
* Respiratory tract, oviduct
* Flagella
* Sperm
25 nm in diameter
what are non-membranous organelles?
- No membrane
- Ribosomes
- Vaults
- Centrioles
- Cytoskeleton
what are ribosomes?
Ribosomes = rRNA and proteins
* Very small (25 nm)
* Important in protein synthesis
* Fixed
* Attached to rough endoplasmic reticulum
* Free
* Loose in cytosol
define the non-membranous organelle vaults
Barrel-shaped organelle
* May function in the transport of molecules
between the nucleus and the cytoplasm
* Linked to programmed cell death (apoptosis)
* Possess vault RNA (vRNA)
