Title: Biochemistry and Cell Biology 101
1Biochemistry and Cell Biology 101
2Biomolecular Quartet
- There are four primary types of biologically
important molecules, known as the biomolecular
quartet - Carbohydrates (carbs)
- Fatty Acids
- Amino Acids
- Nucleic Acids
3Biomolecular Quartet
- Carbohydrates
- Sugars
- Groups called saccharides or polysaccharides
- Often 6 carbon rings
- Sometimes 6-C ladders
- Short term energy supply
- Molecular recognition
4Biomolecular Quartet
- Fatty Acids
- Fats
- Polymers are called lipids
- Lumpy head with multiple straight carbon chains
ending with -COOH - Long term energy storage
5Biomolecular Quartet
- Amino Acids
- Consist of a central carbon surrounded by
- A hydrogen atom
- An amine (NH3) group
- A carboxylic acid (COO) group
- A variable group
- 20 amino acids (8 or 9 are essential)
- Basic protein building block
- Amino Acid (AA), peptide, polypeptide, protein
6Biomolecular Quartet
Essential Amino Acids (cannot be made by body)
- Tryptophan
- Methionine
- Valine
- Threonine
- Phenylalanine
- Leucine
- Isoleucine
- Lysine
- Histidine
Grains
Legumes
7Biomolecular Quartet
- Nucleic Acids
- Consists of
- A pentose (5 carbon sugar)
- A phosphate group
- A purine or pyrimadine (6C ring) base
- Forms the basis of the genetic code
- DNA Adenosine, Cytosine, Guanine, Thymine
- RNA Adenosine, Cytosine, Guanine, Uracil
8Biomolecular Quartet
Alanine GCU, GCC, GCA, GCG
Cysteine UGU, UGC
Aspartate GAU, GAC
Glutamate GAA, GAG
Phenylalanine UUU, UUC
Glycine GGU, GGC, GGA, GGG
Histidine CAU, CAC
Isoleucine AUU, AUC, AUA
Lysine AAA, AAG
Leucine UUA, UUG, CUU, CUC, CUA, CUG
Methionine AUG
Asparagine AAU, AAC
Proline CCU, CCC, CCA, CCG
Glutamine CAA, CAG
Arginine CGU, CGC, CGA, CGG, AGA, AGG
Serine UCU, UCC, UCA, UCG, AGU, AGC
Threonine ACU, ACC, ACA, ACG
Valine GUU, GUC, GUA, GUG
Tryptophan UGG
Tyrosine UAU, UAC
- Amino Acids
- Coded by nucleic acid triplets in DNA/RNA
- 3 letters codon
- 3 letters of 4 types gives 64 combinations to
encode 20 amino acids. - A adenosine
- C cytosine
- G guanine
- U uracil
9DNA
- Two interwoven strings of nucleic acids form the
double helix of DNA.
- 2 strands are complementary
- Adenosine pairs with Thymine
- Cytosine pairs with Guanine
10DNA
- The helix is wound on spools called histones.
- Strings of histones form chromatin fibers.
- The chromatin fibers loop and coil into
chromatids. - Two chromatids joined by a centromere form a
chromosome.
11DNA
- Each chromosome
- 2 short arms (p)
- 2 long arms (q)
- Nomenclature
- TPH1 11p15.3-p14
- Chromosome 11
- p Short arm
- Region 14-15.3
12DNA Structure
- Each chromatid carries several to several
thousand genes (about 20-30K total in humans). - Genes control some characteristic of the
organism. TPH1 on 11p14-15 is 21K BP (1335 BP),
444 AAs
13DNA
- Humans normally have 23 pairs of chromosomes
(46 total) - 22 pairs of autosomal chromosomes
- 2 sex chromosomes XX (female) or XY (male)
14Genetics
- Monogenetic traits
- A single gene controls the presence or absence of
the trait. - Dominant traits One copy required to express the
trait. - Ex. Brown hair, Widows peak, polydactyly,
unattached earlobes, freckles, curly hair,
Huntingtons Disease - Recessive traits Two copies required to express
the trait. - Ex Blond hair, blue eyes, colorblindness,
albinism, PKU, sickle cell anemia, cystic
fibrosis - Homozygous both parental genes the same.
- Heterozygous both parental genes different.
15Genetics
- Polygenetic traits
- Several to many genes involved.
- Most human behavioral and personality traits, and
mental health problems are polygenetic and can be
influenced by environmental factors. - Sex-linked traits
- reside on either the X or Y chromosomes, but X is
usually implied since Y is so small. - Sex-limited traits
- present in both sexes but have an effect in one
sex only, or at least it has a much stronger
effect in one sex than in the other. (ex breast
size, chest hair)
16Genetics/Heritability
- Genetic does not necessarily imply heritable!
- Genes can be inherited, but
- Healthy genes can be changed by
- Random mutations
- Ionizing radiation
- Toxins
- Etc.
17Heritability
- An important question to ask is whether the
observed differences among individuals depend
more on differences in heredity or differences in
environment. - Researchers use the concept of heritability, an
estimate of how much of the variance in some
characteristic within some population is due to
heredity. Range is 0 1.
18Heritability
- Twins
- Twins offer a unique opportunity to separate
nurture (environment) from nature (genetics). - Identical/Monozygotic/MZ both twins have exactly
the same DNA, since they came from a single
fertilized egg. If separated twins show the same
trait, it is most likely genetic (nature). - Fraternal/Dizygotic/DZ the twins have the same
genetic similarity ( ¼ ) as any other siblings.
19Heritability
- How do researchers determine the heritability of
a human trait? - 1st , to compare genetics, researchers compare
the resemblance between monozygotic (identical)
and dizygotic (fraternal) twins. - A stronger resemblance between monozygotic twins
indicates higher heritability.
20Heritability
- 2nd, to examine the contribution of the
environment, researchers examine the differences
between adopted children and their biological and
adoptive parents. - Resemblance to the biological parents indicates
high heritability resemblance to the adoptive
parents indicates low heritability and greater
influence of environmental factors.
21Heritability
- Personality traits 0.5
- MMPI Scales 0.26 0.62, M 0.44
- MPQ - 0.39 0.58
- Schizophrenia, Depression 0.5 0.6
- IQ about 0.7
- Bipolar Disorder 0.8
- Huntingtons 1.0
22Heritability
- Social/Antisocial
- Religiosity
- Conservatism
- Risk Taking/Harm Avoidance
- Anxiety
- Pessimism/Optimism
- Impulsive Aggression
- Persistence
23The Cell
24The Cell
- A cell is the basic structural and functional
unit of all living organisms. - Cells carry on all of the same life functions as
the entire organism. - About 50 trillion cells in the human body.
25The Cell
- Bilipid membrane
- Two lipid membrane layers tightly bound
- Hydrophobic inside, Hydrophilic outside
- The membrane is fluid
- Embedded with channel, structural and recognition
proteins - Maintains internal cellular environment
26Cell Membrane
27The Cell
- Nucleus
- Stores the genetic material
- Surrounded by porous nuclear envelope
- Important genes are copied and mRNA is exported
thru the nuclear pores to the rough ER for
protein synthesis
28The Cell
- Ribosomes
- Created in the nucleolus.
- Synthesize proteins from Aas.
- Endoplasmic Reticulum
- Rough ER
- Contiguous with nuclear membrane
- Embedded with ribosomes
- Protein synthesis
- Smooth ER
- No ribosomes
- Steroid and lipid synthesis
29The Cell
- Golgi Apparatus
- Packages proteins produced by ER into packets
called vesicles.
30The Cell
- Mitochondria
- Energy production glucose-gtATP
- Some cells have only a few mitochrondria.
- Nerves and muscle have hundreds or more.
31The Cell
- Microtubules/ Microfilaments
- Provide cellular structure
- Protein/organelle transport
- Centrioles
- Specialized groups of microtubules.
- Helps divide cell during mitosis.
32The Cell
- Vacuoles
- Storage vesicles
- Peroxisomes
- Contain powerful enzymes for detoxification
- Lysosomes
- Contain digestive enzymes
- Destruction of old cell parts
33The Cell
- Cilia
- Move in unison to propel fluid over cell
- Flagella
- Propels the cell
- Both have a 92 structure
- 9 pairs of microtubules
- Plus a center pair
34The Cell
- Microvilli
- Hair-like projections that increase surface area
- Used for absorption in intestines, nose, lungs
35The Cell
36Cell Reproduction
- At conception there is only one cell.
- 23 chromsomes from ovum, 23 from sperm.
- All cells of the first several generations are
exactly identical. - Specialization starts about the 5th or 6th
generation. - Each generation only gets more specialized.
- Stem cells are unspecialized and can develop into
any type of cell.
37Cell Reproduction
- Mitosis cell division
- The 46 chromosomes are duplicated, temporarily
making 92. - The copies are separated to opposite ends of the
cell. - The cell divides down the middle.
- This leaves two cells, each with 46 again.
38Cell Reproduction
- Mitosis gone bad
- The 46 chromosomes are duplicated, temporarily
making 92. - 45 copies move to one end, 47 to the other.
- The cell divides down the middle.
- The person is now a mosaic some cells differ
genetically!
39Cellular Groups
- Types of attachments between cells
- Tight junctions
- Impenetrable junctions
- Found in the blood-brain barrier
- Gap junctions
- Loose junctions that allow substances to pass
- Important embryonically, before circulation
- Often have connexions, intercellular tubes
- Desmosomes (adhesion junction)
- Structural connection proteins, gap junctions
40(No Transcript)
41Tissues
- A group of connected cells performing a similar
function is called a tissue. - Only 4 types of tissue
- Epithelial (surface) tissue
- Connective tissue
- Muscle
- Nerves
- A group of related tissues which perform a given
function is called an organ.
42The Nerve Cell
- Several specializations from a normal cell
- No centrioles nerves cannot replicate!
- Long life (must last a lifetime)
- Long and narrow vs. round-ish
- Nissl bodies, specialized rough ER
- To handle neurotransmitter synthesis
- Extremely high metabolic rate
- Many more mitochondria than normal cells
- Create action potentials, electrical pulses
43The Nerve Cell
- Cell body
- Biosynthetic center
- Dendrites
- Receptive regions
- Axon
- Arises from the axon hillock
- Impulse generation and transmission
- Ends in telodendria and terminal buttons
44The Nerve Cell
- Classifications
- Multipolar many processes (dendrites axon)
- Most abundant type in body CNS
- Bipolar 2 processes
- Rare, mostly sensory
- (Pseudo)unipolar one process
- Form as bipolar and then the proximal processes
merge into one - Mostly found in the PNS
45Types of Neurons
46The Nerve Cell
- Helpers (glial cells)
- Help during migration
- Schwann cells oligodendrocytes
- Speed transmission
- Astrocytes (CNS)
- Hold nerves in place, anchor to blood supplies
- Microglia
- Monitor nerve health, phagocytosis