Notes, abstracts, papers, exams and problems of Biology

-Nucleic acid: are composed of nucleotides, very large and complex organic molecules that contain the genetic code for that organism.

Nitrogen bases: adenine, thymine, cytosine, guanine & uracil

-DNA replication: means making more DNA

^it occurs in the nucleus(eukaryote cells have nucleus but prokaryotes don't) ^typically happens during interphase   

^it doesn't happen during mitosis(cell division)

^cells replicates its dna before division processes like mitosis and meiosis

^enzymes have the ability to speed up reactions and build up or break down items that they act on

-Types of enzymes:

^helicase-breakdown the 2 strands of DNA

^DNA primase-tells polymerase where to go

^DNA polymerase- replicates dna molecules to build a new strand of dna (20

Chemical Evolution

Chemical evolution refers to the processes that created the biomolecules, and then formed structures called protocells. According to Oparin, the first biomolecules were synthesized when the components of Earth’s primitive atmosphere reacted on contact with each other.

Biological Evolution

Biological evolution refers to the processes that led protocells to become different types of cells, and resulted in all the different organisms ever to have inhabited the Earth. Different types of prokaryotic cells were created from primitive cells: heterotrophic cells, photosynthetic cells, aerobic cells, long and very mobile cells.

Fixist Theories

Fixist theories uphold the idea that the species that currently exist on Earth were created... Continue reading "Chemical and Biological Evolution Theories and Characteristics of Hominids" »

es 3:       x        Cornea                         1   1    2      Dendrites: receive the 

All

Long

I-Parkinson Sx(Amimia/Micrgraphia)(dementia/hyperkinesia)II-2nd Park(Neuroleptic)(CO/Arteriscleoris/encephlaiits)III-Syringomyelia(Sensory loss/Wasting/Long tract/Autonomiv)IV-Tx of M Gravis(Ach(-)(CSD)(Plasmophoresis)(thymectomy)V-Foot Drop(L5...)VI-Open Depressed ScullVII-Cerebral artery aneurysm!(gigantic,sacular)VIII-Sterotactic Techniques used for:^^glioblastoma Histology-Lumbar vertebral Fractures:-Sx provoked by brain tumour!-Multifocal Tumours:-Dx for Cerebral artery aneurysm-Cerebral artery naeurysm Clipped by:

-CN 9+10 Dx:-Lesion CN 5(sensory nuclei)-CN 9 lesion!-Malingnant brain glioma

***T/F:

-CS tract(NOT ) onl from Frontal-BS lesion--->controlateral hemiparesis(T)-Bilateral amr paralysis, Central cord(T)-controlateral Focal

Sliding filament model of contraction

1.ATP binds to a myosin head and forms ADP + P

2. Ca exposes the binding sites on the actin filaments 

3.Cross bridges between myosin head and actin filaments form

4.ATP causes the cross bridges to unbind

Skeletal muscle contration

- Tropomyosin-->7 actin-binding sites to 7 actin monomers In a thin filament 

- Troponin-->complex of 3 subunits(TN-T,TN-I,TN-C-binds Ca)

presence of Ca & TN-->TM can occupy ON And OFF state

OFF -> no Ca ->TM blocks myosin interaction with F-actin

ON -> binding to Ca -> movement of TM exposing myosin binding sites on actin

Smooth muscle contraction -> different from skeletal because of the presence of calmodulin and myosin light chain kinase (MLK) that lead

Saturated Fats

Carbon atoms fully saturated with hydrogen atoms. (meats, animal fats, lard, whole milk, butter, cheese, ice cream, coconut oil, palm oil)

Trans Fatty Acids

Solidified fat forms by adding hydrogen to MUFA and PUFA to increase shelf life

Osteoporosis

Condition of softening, deterioration, or loss of bone mineral density that leads to disability, bone fractures, and even death from medical complications

Protein

Classification for nutrients consisting of complex organic compounds containing nitrogen and forms by combinations of amino acids; the main substances used in the body to build and repair tissues

Amino Acids

Chemical compounds that contain nitrogen, carbon, hydrogen and oxygen; the basic building blocks the body uses to build different... Continue reading "Understanding Nutrition: Fats, Proteins, Vitamins, and Minerals" »

Nerve Impulse

A stimulus occurs, sensory receptors detect the stimulus, sensory neurons receive the information and transmit it to the central nervous system (CNS). The CNS receives the information and a response is decided. Motor neurons transmit the response to the effectors, which carry out the response. The response is given through motor responses carried out by muscles and secretory responses carried out by glands.

Nervous System

The nervous system receives and transmits information rapidly through electrical impulses. Information is transmitted through sensory neurons and processed in the CNS.

Endocrine System

The endocrine system consists of glands that secrete hormones. These hormones are carried in the blood to the cells of the target... Continue reading "Understanding the Nervous and Endocrine Systems" »