Module 1: The Cell Flashcards
The Biomolecules
- carbohydrates
- proteins
- lipids
- nucleic acids
Carbohydrates
- provide energy for body
- contain C, O, H
Lipids
- important structural component
- energy source/storage
- chemical messenger
- contain C, O, H
Proteins
- support
- movement
- transport
- metabolic regulation
- defense
- coordination and control
- contain C, O, H, N
Nucleic Acids
- stores genetic information
- performs protein synthesis
- contain C, O, H, N, P
Function of nucleus
- stores genetic material
- regulates DNA activity
- produces ribosomal subunits
- site of ribosomal RNA is nucleolus
Different types of chromatin
Euchromatin
- active DNA, dispersed
Heterochromatin
- inactive DNA, condensed
Cell membrane proteins
Anchoring proteins
- enable membrane to interact w/ cytoskeleton and external structure
Recognition proteins
- identification system of cell
Receptor proteins
- specific structures, bind to ligands
Carrier proteins
- allow molecules to transfer across membrane
Channels/Transport proteins
- allow entry and exit of substances in large volume
feedback
relationship between sensory receptors and responding effectors
negative feedback
effector acts to oppose message issued by initial stimulus
positive feedback
results in enhancement and escalation of intial stimulus
atom
smallest stable unit of matter
element
a pure substance, consisting only of atoms with the same atomic number
molecule
atoms joined together by a bond
nucleus structure and function
- houses genetic material, regulates expression of genes, produces ribosomal subunits
- usually most prominent feature, nuclear envelope, nucleolus
nucleolus structure and function
- not surrounded by membrane, spherical dark body
- site of rRNA synthesis
nuclear envelope structure and function
- double membrane with openings (nuclear pores)
- allows communication into nucleus
chromatin
compacted DNA wrapped around protein, packed into chromosomes
euchromatin
active DNA, lightly stained, dispersed
heterochromatin
inactive, highly condensed
main steps of transcription
- DNA uncoils
- Gene sequence is exposed
- mRNA strand is assembled by enzymes
main steps of translation
- initiation
mRNA binds to ribosome
tRNA delivers amino acids - elongation
Amino acids link to form polypeptide chain - termination
Proteins are released and further modified
Why are proteins important?
proteins dictate everything that happens in our cells and the structure of our body
Structure and function of cytosol
- varies in composition and consistency
- intracellular fluid surrounding organelles
Structure and function of ribosomes
- Contain high content of RNA; attach to RER; consists of small subunit and large subunit
- Sites of protein synthesis
Structure and function of rough ER
- continuous with nuclear envelope studded with ribosomes
- responsible for structural modification of proteins
Structure and function of smooth ER
- lacks ribosomes
- contain unique enzymes that synthesise fatty acids & steroids
Structure and function of golgi complex
- 2 surfaces (entry and exit); 3 - 20 cisternae (small flattened membranous sacs)
- sorts and packages proteins exiting RER
Structure and function of vesicles
- membrane bound organelles containing water/proteins/enzymes/hormones/wastes
- Carrier (transport) and delivery (secretory)
Structure and function of mitochondria
- Double membrane; Contains mitochondrial DNA ; Inward folds called cristae; Inner space called matrix
- Site of ATP production
Structure and function of lysosomes
- Membrane enclosed vesicles formed from Golgi complex
- Contain many enzymes that break down molecules
Structure and function of cytoskeletons
- Skeleton/framework of the cell
- Provides strength and shape, enables movement
