Intro Flashcards
the science concerned with the chemical basis of life
• T h e science c o n c e r n e d with the chemical
constituent of living cells and with the reactions
and processes they undergo.
Biochemistry
Life sciences that needs knowledge of
Biochemistry
• G e n e t i c s
• Physiology
• Pharmacology
• Immunology
Toxicology
• Pathology
• Microbiology
• Zoology
• Botany
Basic building blocks of life
• Smallest living unit of an
organism
• Grow, reproduce, use energy,
adapt, respond to their
e n v i r o n m e n t
• Many cannot be seen with the
naked eye
• may be an entire
o r g a n i s m or it m a y b e o n e o f
billions o f cells t h a t m a k e u p t h e
organism
Cell
is a simple, single-celled (unicellular).
organism that lacks a nucleus, or any other membrane-bound organelle. it is found in the central part of the cell: a darkened region called the nucleoid.
• include bacteria & lack a nucleus or membrane - bound structure
called organelles
prokaryotic cell
cell that has a
m e m b r a n e - b o u n d nucleus and
other membrane bound compartments or sacs, called organelles, which have
specialized functions.
• include most other cells & have a
nucleus and membrane - bound
organelles (plants, fungi, &
animals )
Eukaryotic cell
What do prokaryotes and eukaryotes
have in common?
- D N A
- Cell (or plasma) membrane
- Ribosomes
- Cytoplasm
A lipid/protein/carbohydrate complex, providing a barrier and containing transport and signaling systems.
Cell membrane
Double membrane surrounding the chromosomes and the nucleolus. Pores allow specific communication with the cytoplasm. The nucleolus is a site for synthesis of RNA making up the ribosome
Nucleus
Surrounded by a double membrane with a series of folds called cristae. Functions in energy production through metabolism.
Contains its own DNA, and is believed to have originated as a captured bacterium.
Mitochondrian
A network of interconnected membranes forming channels within the cell. Covered with ribosomes (causing the rough appearance) which are in the process of synthesizing proteins for secretion or localization in membranes
Rough endoplasmic reticulum (RER)
A network of interconnected membranes forming channels within the cell. A site for synthesis and metabolism of lipids. Also contains enzymes for detoxifying chemicals including drugs and pesticides.
Smooth endoplasmic reticulum
A series of stacked membranes. Vesicles (small membrane surrounded bags) carry materials from the RER to it. Vesicles move between the stacks while the proteins are “processed” to mature form. Vesicles then carry newly formed mebrane and secreted proteins to their final destinations including
secretion or membrane localization.
Golgi apparatus
A membrane bound organelle that is responsible for degrading proteins and membranes in the cell, and also helps degrade materials ingested by the cell.
Lysosymes
Produce and degrade hydrogen peroxide, a toxic compound that can be produced during metabolism.
Peroxisomes or Microbodies
enclosed by the plasma membrane, liquid portion called cytosol
and it houses the membranous organelles.
Cytoplasm
Arrays of protein filaments in the cytosol. Gives the cell its shape and provides basis for movement.
E.g. microtubules and microfilaments.
Cytoskeleton
What are the two Cell membrane models
- Lipid bilayer or unit membrane theory
- Fluid mosaic model
• Originally proposed by American anatomist, physician and biochemist James David Robertson
• It considers the plasma membrane to be composed of two layers of phospholipid between two surface layers of proteins, with the hydrophilic “head” groups of the phospholipids facing the protein layers and the hydrophobic “tail” groups of the phospholipids aligned in the interior
LIPID BILAYER OR UNIT MEMBRANE
THEORY
By S.J. Singer and G.L. Nicolson
• According to this model, the cell membrane consists of globular proteins embedded in a dynamic fluid, lipid bilayer matrix. These proteins provide a pathway for the selective transfer of certain polar molecules and charged ions through the lipid barrier.
• “protein icebergs in an oily sea”
FLUID MOSAIC MODEL
• Just like cells are building blocks of tissues likewise molecules are building blocks of cells.
• Animal and plant cells contain approximately 10, 000 kinds of molecules
• Water constitutes 50-95% of cells content by weight.
• Ions like Na+, K+ and Ca+ may account for another 1%
• Almost all other kinds of these are organic (C, H, N, O, P, S)
• Infinite variety of molecules contain C.
• Most of these are considered to be derived from hydrocarbons.
• The chemical properties of organic are determined by their functional groups and it has more than one.
Bio-molecules
(Major Classes of small Bio-molecules)
- Building blocks of proteins 20 commonly occuring
R-group
or side chain
a carbon
*H3N
a. amino group
carboxy! group
• Contains amino group and carboxyl group function groups (behavioral properties)
• R Group (side chains) determines the chemical properties of each amino acids.
• Also determines how the protein folds and its biological function.
• Individual amino acids in protein connected by peptide bond.
• Functions as transport proteins, structural proteins, enzymes, antibodies, cell receptors.
Amino acids
Carbohydrates most abundant organic molecule found in nature.
• Initially synthesized in plants from a complex series
• Basic unit is monosaccharides .
• Monosaccharides can form larger molecules e.g. glycogen, plant starch or cellulose.
Functions
• Provide energy through metabolism pathways and cycles.
• Supply carbon for synthesis of other compounds.
• Form structural components in cells and tissues.
• Intercellular communications
- store energy in the form of starch (photosynthesis in plants) or glycogen in (animals and humans)
Sugar
• Are monocarboxylic acid contains even number C atoms
• Two types: saturated (C-C sb) and unsaturated (C-C db)
• are components of several lipid molecules.
• • E,g. of lipids are triacy glycerol, streiods (cholestrol, sex hormones), fat soluble vitamins.
Functions
• Storage of energy in the form of fat
• Membrane structures
• Insulation (thermal blanket)
• Synthesis of hormones
Fatty acids
any member of a class of organic compounds in which the molecular structure comprises a nitrogen-containing unit (base) linked to a sugar and a phosphate group.
Functions
• are of great importance to living organisms, as they are the building blocks of nucleic acids, the substances that control all hereditary characteristics.
Nucleotides
total sum of the chemical reaction happening in a living organism (highly coordinated and purposeful activity)
metabolism
energy requiring biosynthetic pathways
anabolism
degradation of fuel molecules and the production of energy for cellular function
catabolism
All reactions are catalyzed by?
enzymes
primary functions of metabolism are?
a. acquisition & utilization of energy
b. Synthesis of molecules needed for cell structure and functioning (i.e. proteins, nucleic acids, lipids, & CHO
c. Removal of waste products
Is a chemical substances found within a living organism.
Biochemical substances
Contain single circular chromosomes
DNA can interact with the cytoplasm, transcription and translation occur simultaneously.
Most contain one copy of each gene
Nucleolus absent
Membrane bound cell organelles absent
Cell division by fission or budding
Prokaryotes
Multiple linear chromosomes
Transcription occur in nucleus, and translation occur in cytoplasm
Most contain two copies of each gene (diploid)
Nucleolus present
Membrane bound cell organelle present
Cell division by mitosis or meiosis
Eukaryotes
Protein and RNA complex responsible for protein synthesis
Ribosome
Main source of energy:
Carbohydrates
it is acellular and only rely on hosts
virus
DNA-DNA
Process of Replication
DNA-RNA
Process of Transcription
RNA-RIBOSOME
Process of Translation
it covers the cell
cell membrane
it covers the organelle
Plasma membrane
Glycolysis occurs at _________
cytoplasm
