1. Explain the importance of chemistry and chemical reactions.
- make up all body substances
- perform all body activities
- provide energy for all body activities
2. Explain the importance of cells, proper cell structure and functioning.
- cells and substances they produce make up
all body parts and perform all body functions
- abnormal or unfavorable conditions for cells
result in abnormal or unfavorable body structure and functioning
3. Describe the hierarchy of structure and functioning in the body.
- cells are grouped with similar cells to form tissues, which are combined to form organs, which are combined to form systems, which are combined to form the individuals person
4. Name important body chemicals and list their main functions
- water - solvent, lubricant, cushion, temperature
regulation, cell shrinking and swelling (osmosis), acid/base balance
- carbohydrates = single sugars or chains
of sugars - energy, building materials, cell receptors
- nucleic acids = single nucleotides or chains
of nucleotides (e.g., ATP, DNA, RNA) - individual nucleotides carry energy,
chains provide information that directs cells activities (i.e., genes,
protein synthesis for structure and regulating enzymatic reactions)
- proteins = chains of amino acids - building
materials, receptors, hormones, enzymes, antibodies
- lipids = diverse types of molecules (e.g.,
glycerides, phospholipids, steroids) - energy, building materials, hormones
- molecular complexes = glycoproteins, mucopolysaccharides,
lipoproteins - building materials, communication, transport of materials
- free radicals = atoms or molecules with
an unpaired electron - regulating body functions, defense activities
5. Describe methods of formation of, harmful effects from, and body defense mechanisms against free radicals.
- formed during normal body reactions (e.g.,
signaling, energy production, lipid chain reactions)
and when a free radical damages a molecule
- cause oxidation = damage to nucleic acids,
protein, and lipids -> damage to cells and secretions from cells -> damage
to body structure and functioning
- body defense mechanisms reduce free radical
production, remove free radicals, and repair oxidative damage from free
radicals
6. Describe methods of formation of and harmful effects from glycation.
- glycation = binding of glucose or other sugar
molecules to amino acids and to proteins - > advanced glycation end-products
- cause distortion of proteins, promotion
of free radical formation and oxidative damage, reduction in defense mechanisms
against free radicals, promotion of age-related abnormalities and diseases
(e.g., high blood pressure, atherosclerosis, Alzheimer's disease, diabetes
mellitus)
7. List main parts of cells and their functions.
- cell membrane - hold cell together, regulate
entry and exit of materials, receive messages
- cytoplasm - supports parts, produces and
stored substances, provides energy
- endoplasmic reticulum - compartmentalizes
cells, manufactures lipids and proteins
- Golgi apparatus - collects, packages, and
exports materials produced by a cell
- vacuoles - stores substances including enzymes
for defense and digestion within the cell
- mitochondria - interconverts substances,
produces energy, main source of free radicals
- microtubules and microfilaments - provide
cell with support, transport of materials, and movement
- nucleus - houses genetic information as
DNA in chromosomes to control cell activities
8. Explain how genes control cell structure and function and body structure and function.
- 46 chromosomes, each containing many genes
- gene = segment of DNA with a message (e.g.,
instruction to make a protein)
- copy of DNA in form of mRNA carries instruction
from gene to cytoplasm
- ribosomes "read" mRNA to make protein
- proteins make up body structure, regulate
production of other body structural molecules (e.g., carbohydrates, lipids),
and regulate body activities (i.e., as enzymes)
- telomere = end region of a chromosome
9. Describe the main steps in cell reproduction by mitosis.
- cell duplicates DNA in each chromosome
- only part
of the telomere is duplicated, using the enzyme telomerase
- chromosomes are lined up in a row, copies
are separated with one of each moving to opposite ends of the cell
- cell pinches into two portions, each with
one set of chromosomes
10. List reasons why mitosis is important.
- body growth, repair of damaged parts, replacement of damaged or dead cells
11. Describe the Hayflick limit and its possible importance to aging and disease..
- in experimental settings, many types of human
body cells can undergo a limited number of mitoses and then cannot divide
again. This number = Hayflick limit = replicative senescence
- the Hayflick limit decreases as the age
of the person from whom the cells are taken increases
- since the Hayflick limit seems to mimic
or demonstrate aging processes in cells, understanding the Hayflick limit
or controlling it may lead to understanding or control of aging or of certain
diseases (e.g., cancer)
12. Describe neoplasia and its two main forms (i.e., benign neoplasia,, cancer).
- neoplasia = uncontrolled continuous cell
reproduction
- benign neoplasia
= neoplasia that does not spread
- cancer = malignant
neoplasia = neoplasia that spreads
- aging -> increased incidence of neoplasia
- increases
in the number and proportion of elders -> increased incidence and importance
of neoplasia
(See also pp. 66-67 and neoplasias in other
body systems)
13. Describe apoptosis and its relevance in aging.
- apoptosis = deliberate programmed cell death
- important during early development, may
mimic certain age changes, unknown relevance in aging
14. Explain relationships between studying aging and studying genetics.
- genes influence or determine XL and ML, interactions
between lifestyle and age-related changes, age-related diseases (e.g.,
Alzheimer's diseases, progeroid syndromes, Werner's disease)
- understanding the relationships between
genetics and diseases that mimic aging may lead to better understanding
of normal aging
15. Describe the structure and functions of intercellular materials.
- amorphous materials = fluids, gels, and hard
substances
- fibers include collagen (strong, flexible)
and elastin (weak, elastic)
- intercellular materials influence transport
of materials, support, cushioning, binding, body movements, and other physical
properties of the body
16. Distinguish between evolutionary theories of aging and physiological theories of aging.
- evolutionary theories deal with how and why
aging came into existence in living things over eons of time
- physiological theories deal with how an
why aging occurs in present day organisms
17. Distinguish between programmed theories of aging and stochastic theories of aging.
- programmed theories assume that aging is
a planned process with specific causes
- stochastic theories assume that aging occurs
because of chance events
18. List evolutionary theories of aging.
- disposable body theory, antagonistic pleiotropy theory, accumulation of late-acting error theory
19. Describe, compare and contrast the disposable body theory, the antagonistic pleiotropy theory, and the accumulation of late-acting error theory of aging.
- disposable body theory - aging occurs because
the body allocates only enough resources to prevent it to ensure adequate
reproduction. Lack of additional resource allocation allows deterioration
of the body = aging. A stochastic theory.
- antagonistic pleiotropy theory - genes that
promote activities that are helpful in early life promote activities that
are harmful in later life. These harmful effects = aging. A programmed
theory
- accumulation of late-acting error theory
= harmful genes that are not allowed to act until later in life have not
been eliminated by natural selection. Over eons, these harmful genes have
accumulated through mutations. The result of their activities = aging.
A programmed theory.
20. List and briefly describe physiological theories of aging (genetic, rate of living, free radical, mitochondrial, mitochondrial DNA, clinker, cross-linkage, hormone, calcium, immune system, wear and tear, network) and their relevance to aging.
genetic
genetic timers
- genetic
biography = genes used in sequence, and 1st part of story = aging
- antagonistic
pleiotropy theory = genes that promote activities that are helpful in early
life promote activities that are harmful in later life. These harmful effects
= aging
- genetic
clock = certain genes monitor age and signal aging to begin
- death
gene = certain gene(s) signal aging in order to produce death
- telomere
theory = loss of telomeres disrupts normal gene activities -> aging
limited gene usage
- somatic
mutation = usage damages genes -> faulty information -> aging
- faulty
repair = decline in DNA repair -> genetic errors -> faulty information
-> aging
- error
catastrophe = damage in genetic transcription to RNA or translation to
protein -> cascade of errors -> aging
rate of living theory - normal metabolism causes progressive damage (e.g., free radical damage) = aging. Faster metabolism -> faster aging -> shorter XL and ML.
free radical = free radicals produced by environmental or cell metabolic processes -> damage to cell components (i.e., DNA, proteins, lipids) -> aging
mitochondrial theory = mitochondria produce free radicals and regulate signaling substances. Damaged mitochondria produce more free radicals and do not regulate signaling substances well -> detrimental effects = aging
mitochondrial DNA theory = mitochondrial DNA sustains more damage from free radicals and other causes that does DNA in nuclear chromosomes. Mitochondria with damaged DNA produce less energy and most free radicals -> detrimental effects = aging
clinker = accumulation of harmful chemicals (e.g., lipofuscin, amyloid, glucose) -> damaged functioning = aging
cross-linkage = linking of molecules (e.g., collagen,
glucose) -> improper structure and functioning = aging
- glycation theory = most harmful cross-links
result from glycation from glucose
hormone theories
- hormone imbalance
= decreased regulation of and by the endocrine system (e.g., insulin, growth
hormone, glucocorticoids, reproductive system hormones) -> disruption of
coordination of body functions -> detrimental effects = aging
calcium theory
- declining regulation of calcium concentrations
and movements -> declining regulation of body activities = aging
immune system
- autoimmunity = immune system damages
and destroys normal body components -> aging
- immune deficiency = inadequate immune
functioning -> protection -> damage -> aging
- immune dysregulation = combination
of autoimmune activities plus immune deficiencies plus imbalance of signals
from the immune system to other systems -> detrimental effects = aging
wear and tear
- random accumulation of injuries
-> aging
network theories
- combinations and interactions among
two or more of the other theories
21. Explain why forming and testing theories of aging are important.
- forming testable hypotheses and theories
-> further research -> increased understanding of aging
- once confirmed -> modulation or control
of aging; ability to distinguish aging from environmental, abnormal and
disease factors
© Copyright 1999 - Augustine G. DiGiovanna - All rights reserved.
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PERSPECTIVES by Augustine G. DiGiovanna, The McGraw-Hill Companies, New
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