prelims Flashcards by REEMA BACHO

Study of cells

Cytology

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Study of tissues

• Histology

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Study of structures & parts

• Anatomy

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-Study of functions of organisms & their parts

• Physiology

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study of the different forms of organisms

• Morphology

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Study of heredity

• Genetics

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Study of the interaction of organisms with their
environment

• Ecology

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Study of the diversity of organisms (classification
based on their evolutionary relationships– Taxonomy)

• Systematics

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– study of insects

• Entomology

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study of amphibians and reptiles

• Herpetology

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study of fishes

• Icthyology

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study of mammals

• Mammalogy

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study of birds

• Ornithology

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study of protozoa

• Protozoology

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Two approaches are used to understand natural causes for
natural phenomena

• Discovery science —uses verifiable observations and
measurements to describe science
• Hypothesis-based science —uses the data from discovery
science to explain science
– This requires proposing and testing of hypotheses

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—uses verifiable observations and
measurements to describe science

• Discovery science

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—uses the data from discovery
science to explain science
– This requires proposing and testing of –

• Hypothesis-based science

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is a proposed explanation for a set of
observations

A hypothesis

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is supported by a large and usually growing body
of evidence

• A theory

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is the genetic (hereditary) material of all cells
– A gene is a discrete unit of –
– The chemical structure of – accounts for its function
– The diversity of life results from differences in – structure
from individual to individual

DNA

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is a discrete unit of DNA

A gene

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the complex organization of living things (Cells
as the basic unit of life)

• Order

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—an ability to maintain an internal
environment consistent with life

• Regulation

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—consistent growth and
development controlled by DNA

• Growth and development

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—acquiring energy and transforming it to a form useful for the organism

• Energy processing/Metabolism

—an ability to respond to environmental stimuli

• Responsiveness/ Irritability

—the ability to perpetuate the species

• Reproduction

—acquisition of traits that best suit the organism to its environment (evolutionary adaptation)

• Adaptability

animals (depend on other organisms for food)

Heterotrophs

plants (can make their own food)

Autotrophs

animals (Can move on their own)

Motile

(cannot move on their own)

Stationary

 Carbon (C) element as the backbone (except CO2)  C usually accompanied with Hydrogen (H)  Associated with living organisms  Ex. Sugars, DNA, fats, proteins

ORGANIC

 Do not contain C (except CO2)  Not associated with living organisms  Ex. water, gases, salts, metals,

INORGANIC

 Carbohydrates  Lipids  Proteins  Nucleic Acids

ORGANIC COMPOUNDS (Biomolecules/Macromolecules)

are found throughout the cell both as parts of cell structures and as enzymes. The flagellum is a structure involved in swimming motility.

Proteins (brown)

DNA (green) is found in the nucleoid of prokaryotic cells and in the nucleus of eukaryotic cells. RNA (orange) is found in the cytoplasm (mRNA, tRNA) and in ribosomes (rRNA).

(b) Nucleic acids.

are located in the cell wall and occasionally in internal storage granules.

are found in the cytoplasmic membrane, the cell wall, and in storage granules.

(d) Lipids (blue)

=C,H,O

Carbohydrates

1. Monosaccharides –1 sugar (building block of CHO) 2. Disaccharides –2 sugars 3. Polysaccharides –many sugars

Types of Carbohydrates:

–1 sugar (building block of CHO)

1. Monosaccharides

–blood sugar

eg. glucose

–fruit sugar

fructose

–a sugar found in milk

galactose

–2 sugars

2. Disaccharides

- table sugar ( 1 glucose + 1 fructose)

eg. Sucrose

–malt sugar ( 2 glucose)

maltose

–milk sugar ( 1 glucose + 1 galactose)

lactose

–many sugars

3. Polysaccharides

–storage form of sugars in plants

eg. Starch

- storage form of sugars in animals; in liver & muscles

Glycogen

- in cell wall of plants

Cellulose

–in exoskeletons of insects & crustaceans; in cell wall of fungi

Chitin

eg. glucose –blood sugar fructose –fruit sugar galactose –a sugar found in milk

1. Monosaccharides –1 sugar (building block of CHO)

eg. Sucrose- table sugar ( 1 glucose + 1 fructose) maltose –malt sugar ( 2 glucose) lactose –milk sugar ( 1 glucose + 1 galactose)

2. Disaccharides –2 sugars

eg. Starch –storage form of sugars in plants Glycogen - storage form of sugars in animals; in liver & muscles Cellulose- in cell wall of plants Chitin –in exoskeletons of insects & crustaceans; in cell wall of fungi

3. Polysaccharides –many sugars

 Source of energy (E)  Stores E  Structural functions

Functions of Carbohydrates

= (C, H, less O)

Lipids

= heterogenous: no common bldg. block but all are common in terms of physical characteristics:  eg. Not soluble in water but soluble in non-polar solvents (eg. alcohols, chloroform, ether)

lipids Building block

1. True Fats (Triglycerides) = 3 Fatty acids + 1 glycerol 2. Phospholipids - 2 fatty acids+ 1 phosphate + 1 glycerol 3. Sterols - common in containing ring structures

Types of lipids:

= 3 Fatty acids + 1 glycerol

True Fats (Triglycerides)

- w/o double bond; solid at room temp eg. Animal fats, beeswax, ear wax

a) Saturated fats

- w/ double bond; remain liquid at room temp eg. Plant/vegetable oils (olive oil, peanut oil, soya oil, corn oil, etc.)

b) Unsaturated fats

- 2 fatty acids+ 1 phosphate + 1 glycerol - found in cell membrane of all cells (arranged in bilayer)

2. Phospholipids

- common in containing ring structures eg. Cholesterol, Vitamins ( water- insoluble vitamins such as Vit. E, Vit. K, Vit A), Progesterone (female hormone), Testosterone (male hormone)

3. Sterols

 Source of energy (E)  Stores E  Structural functions  Building blocks of hormones, vitamins  Insulates the body

Functions of Lipids

= C, H, O, N, some S

Proteins

: amino acids (a.a) essential a.a.-not synthesized by the body non-essential a.a.- synthesized by the body

 Proteins Building block

–sequence of amino acids (a chain of polypeptide) eg. Ala-Lys-Val- Leu-His- Met- Cys

1. Primary structure

–interaction between or within polypeptides A) α- Helix –eg. keratin B) β- pleated sheet –eg. fibroin

2. Secondary structure

–bending, twisting, coiling of polypeptides eg. some antibodies, enzymes

3. Tertiary structure

–applies to multimeric proteins eg. Hemoglobin in blood eg. Rubisco (a photosynthetic enzyme in plants with both tertiary and quaternary structure)

4. Quaternary structure

 Source of energy (E)  Stores E  Structural functions  Act as biological catalysts (enzymes)  Protection from diseases (antibodies)  Other varied functions depending on the kind of proteins

Functions of Proteins

= C, H, O, N, P

Nucleic Acids

Nucleic Acids Building block:

Nucleotides

Components of Nucleotide:

1. Phosphate (PO4-) 2. 5-C sugar 3. Nitrogenous Bases

The two-carbon nitrogen ring bases (adenine and guanine) are

purines,

the one-carbon nitrogen ring bases (thymine and cytosine) are

pyrimidines.

 Double stranded helix  A, T, C, G as N-bases  genetic material (organism’s blueprint)

DNA

 Single stranded  A, U, C, G as N-bases  needed for making proteins

RNA

- a high energy carrier

3. Adenosine TriPhosphate (ATP)

– transfer energy eg. Nicotinamide Adenine Dinucleotide (NAD), Flavin Adenine Dinucleotide (FAD)

4. Co-enzymes

 Informational macromolecules- DNA –genetic material (organism’s blueprint) RNA –needed for making proteins  Carry energy (ATP)  Transfer energy (Co-enzymes)

Functions of Nucleic Acids

1. Water 2. Gases 3. Inorganic Salts 4. Acids, Bases, Buffers

INORGANIC COMPOUNDS

 70-90% by wt.  Universal solvent  Needed for metabolic processes  Replaces body f luids  Regulates body temperature

1. Water

1. High boiling point 2. High heat capacity 3. High heat of vaporization 4. High surface tension

1. Water Characteristics:

 Oxygen (O2) –for maintenance of life (respiration)  Carbon dioxide (CO2) –for manufacturing of food (photosynthesis)  Nitrogen gas (N2) - ???

2. Gases

–for maintenance of life (respiration)

 Oxygen (O2)

–for manufacturing of food (photosynthesis)

 Carbon dioxide (CO2)

–needed by the body in small amounts (Trace Minerals/ Micronutrients) Examples: NaCl (table salt) Calcium carbonate Ferrous sulphate MnSO4 ZnSO4

3. Inorganic Salts

–high H+ pH: 1-6 sour taste litmus: blue to red eg. Hydrochloric acid (inorganic) –in stomach citric acid in citrus fruits, acetic acid in vinegar –organic acids

 Acids

–high OH- pH: 8-14 bitter taste litmus: blue to blue eg. Soap, baking soda, NaOH

 Bases

–a substance or combination of substances that resist change in pH when an acid or a base is added Eg. Carbonate (H2CO3) –Bicarbonate ion (HCO3-) == found in blood and tissue f luids

 Buffers

All organisms are composed of cells  Cell is the smallest functional unit of life  Cells arise from pre-existing cells  The characteristics of an organism depend on each individual cells  Continuity of characteristics is maintained through the genetic material  Energy flow occurs within cells

Modern Cell Theory

“false” nucleus Naked DNA No organelles

PROKARYOTE

“true” nucleus Membrane-bound nucleus Membrane-bound organelless

eukaryote

 Ave 1-2 um in dia.  No nucleus  Without membrane bound organelles  Circular, Naked DNA (nucleiod)  unicellular  Divides by fission  Cytoskeletons absent  Not capable of endocytosis & exocytosis  70S ribosomes  Eg. bacteria, cyanobacteria (BGA), mycoplasmas

Prokaryotic

 >10-100 um  With nucleus  With membrane bound organelles  DNA packed in chromosomes  Unicellular/multicellular  Divides by mitosis & meiosis  w/ cytoskeleton  Capable of endocytosis & exocytosis  80S ribosomes  Eg. plants, animals, fungi, algae, protozoans

Eukaryotic

• Also called cell/cytoplasmic membrane • Fluid (as described by the Fluid Mosaic Model) Functions: 1) Regulate the transport of molecules in & out of the cell 2) Site of enzyme specific activity

PLASMA MEMBRANE

 For tissue organization  For cell adhesion & cell to cell recognition

CELL COAT

 Thick fluid  80% water — containing amino acids, lipids, carbohydrates, ions, and enzymes  Site of many chemical reactions  Suspends organelles & other substances

CYTOPLASM

 “control center” bec. it coordinates all the cell's activities, which include growth, intermediary metabolism, protein synthesis, and reproduction (cell division).  it stores the cell's hereditary material, or DNA

NUCLEUS

– where ribosomes are produced

 Nucleolus

– threadlike structures inside the nucleus that carries the genetic material (where DNA is packed)

 Chromosomes

 processes, and transports a wide variety of biochemical compounds for use inside and outside of the cell

ENDOPLASMIC RETICULUM

- contains ribosomes - site of protein synthesis

 Rough ER

- w/o ribosomes - for production of lipids & hormones

 Smooth ER

 On the cytoplasm as free ribosomes and in rough ER  Synthesize proteins  Produced in the nucleolus

RIBOSOMES

 also called Golgi body or Golgi complex  found in both plant and animal cells  composed of membrane- covered sacs called cisternae  the packaging and shipping/distribution department for the cell's chemical products.

GOLGI APPARATUS

 double-membraned  site of ATP synthesis via Cellular Respiration  power generator of the cell, converting oxygen and nutrients into adenosine triphosphate (ATP)

MITOCHONDRION

 gives shape to the cell; protoplasmic streaming & bldg blocks of cilia, centriole (direct the cell during cell division), basal bodies & flagella (locomotory structure)

MICROTUBULES

 for strength when exposed to mechanical stress; muscle contraction

MICROFILAMENTS

 maintain cell shape; suspend & organize organelles; interconnect cytoskeletal elements & organize enzymes attached to them

INTERMEDIATE FILAMENTS

- “garbage system”of the cell - Contain hydrolytic enzymes for digestion of biomolecules; protect cell from foreign materials; digest subcellular parts as immediate fuel during cell starvation (“suicidal bag”)

Lysosomes

Peroxisomes - contain enzymes for oxidation of substances Glyoxisomes –contain enzymes for conversion of fats to carbohydrates

 Microbodies

- contain enzymes for oxidation of substances

Peroxisomes

–contain enzymes for conversion of fats to carbohydrates

Glyoxisomes

 A newly discovered organelle ( 1990’s)  Cytoplasmic ribonucleoproteins shaped like octagonal barrels (as the shape of nuclear pore)  Thousands in a cell  Cellular “trucks” – dock at nuclear pores, pick up molecules synthesized in the nucleus & deliver to various places in the cell (eg. mRNA to ribosomes for protein synthesis)

VAULTS

Membranes are composed of

phospholipids and proteins

 Membranes are commonly described as a ---  This means that the surface appears mosaic because of the proteins embedded in the phospholipids and fluid because the proteins can drift about in the phospholipids

fluid mosaic

Many membrane proteins function as either of the following:

 Enzymes  signal transduction  Transport

Because membranes allow some substances to cross or be transported more easily than others, they exhibit ----  Nonpolar molecules (carbon dioxide and oxygen) cross easily  Polar molecules (glucose and other sugars) do not cross easily

selective permeability

- movement of substances from higher to lower concentration without the expenditure of energy Example: diffusion of gases in & out of a) blood cell b) plant cell

Simple diffusion

 movement of substances across the membrane from higher to lower concentration without the expenditure of energy  random movement of molecules  driven by the Law of Entropy (tendency to move from orderliness to a less ordered state)

Passive Transport

--- is a process in which particles spread out evenly in an available space  Particles move from an area of more concentrated particles to an area where they are less concentrated  This means that particles diffuse down their concentration gradient  Eventually, the particles reach equilibrium where the concentration of particles is the same throughout

Diffusion

 Particles move from an area of more concentrated particles to an area where they are less concentrated  This means that particles diffuse down their ----

concentration gradient

- movement of substances from higher to lower concentration without the expenditure of energy & with the aid of transport proteins (TP) Example: glucose transport

Facilitated diffusion

--- movement of water molecules from higher to lower concentration without the expenditure of energy  Tonicity is a term that describes the ability of a solution to cause a cell to gain or lose water – Tonicity is dependent on the concentration of a nonpenetrating solute on both sides of the membrane 1. hypertonic - high solute concentration, low water concentration 2. hypotonic - low solute concentration, high water concentration 3. isotonic - solute concentration= water concentration

Osmosis

--is a term that describes the ability of a solution to cause a cell to gain or lose water –-- is dependent on the concentration of a nonpenetrating solute on both sides of the membrane 1. hypertonic - high solute concentration, low water concentration 2. hypotonic - low solute concentration, high water concentration 3. isotonic - solute concentration= water concentration

 Tonicity

- high solute concentration, low water concentration

1. hypertonic

- low solute concentration, high water concentration

2. hypotonic

- solute concentration= water concentration

3. isotonic

 movement of substances across the membrane against a concentration gradient (from lower to higher concentration) using energy and with the aid of transport proteins Example: Ca+ – pumped by active transporter across muscle cell membrane Na+, H+ = enters the cell by diffusion but pumped out from the cell by active transport

ACTIVE TRANSPORT

 Movement of large substances across the membrane by forming vesicles that fuse with the membrane

BULK TRANSPORT

–is used to import substances useful to the livelihood of the cell Types: 1. Phagocytosis – “cell-eating” (engulfment) eg. WBC’s engulf bacteria, amoebas engulf microorganisms 2. Pinocytosis – “cell-drinking” eg. Kidney cells take up water to maintain fluid balance 3. Receptor-mediated endocytosis – requires the aid of a receptor protein to take up substances eg. intestinal cells take up large molecules from the inside of gut

Endocytosis

– “cell-eating” (engulfment) eg. WBC’s engulf bacteria, amoebas engulf microorganisms

1. Phagocytosis

– “cell-drinking” eg. Kidney cells take up water to maintain fluid balance

2. Pinocytosis

– requires the aid of a receptor protein to take up substances eg. intestinal cells take up large molecules from the inside of gut

3. Receptor-mediated endocytosis

- is used to export bulky molecules, such as proteins or polysaccharides eg. Sciatic nerve releases acetylcholine (a neurotransmitter) to initiate muscle contraction

Exocytosis

- the sequence of events in a eukaryotic cell between one cell division & the next.

THE CELL CYCLE

(“Resting Stage”) Gap 1 (G1) phase= growth phase 1 Synthesis (S)-phase = most critical stage Gap 2 (G2) phase= growth phase 2

I.Interphase

(M-phase)/Nuclear Division - immediately followed by cytoplasmic division

II.Mitosis

– production of a cell into 2 cells of equal amount of DNA as the parent cell - involves mostly somatic cells (body cells) - produces 2 identical diploid (2n) cells

Mitosis

- reductional cell division - involves gametes or sex cells in animals (gametic meiosis) or spores in plants & fungi (sporic meiosis) - produces 4 unidentical haploid (n) cells

2. Meiosis

(Karyokinesis)= Mitosis - follows the Interphase (G1, S-phase, G2)

I. Nuclear Division

( Cytokinesis) - Immediately follows nuclear division - it is followed by cell growth

II. Cytoplasmic Division

 Nuclear membrane intact  DNA synthesis ( chromosomes are duplicating)  Growth (Gap) phase  Chromatin – highly dispersed state of DNA

Interphase

– highly dispersed state of DNA

 Chromatin

- Nuclear membrane disintegrating - Thickening, coiling & condensation of duplicated chromosomes - Formation of centriole (in animals) & spindle fibers (plants & animals)

Prophase

- produces spindle fibers forming astral rays

Centriole

direct the chromosomes during cell division

Spindle fibers-

- Nuclear membrane disintegrated - Chromosomes align at the center of the cell - Spindle poles at opposite ends

Metaphase

- Nuclear membrane still disintegrated - Sister chromatids separate & move at opposite poles - Cytoplasmic division is underway - Formation of cleavage furrow in animal cell & primary cell wall in plant cell

Anaphase

- Nuclear membrane re-forms - Chromosomes de-condense characteristic of interphase

Telophase

- fusion of an egg cell & sperm cell to form a diploid zygote egg cell + sperm cell ==== zygote (1n) (1n) (2n)

Fertilization

 Maintain constant number of chromosomes from one generation to another  Produces variable genes that increases chance of survival

advantages of meiosis

prelims Flashcards

(157 cards)