Pre-Med

Question 1

The Progressive Structure of Living Things

Answer 1

Atoms, Molecules, Macromolecules, Organelles, Cells, Tissues, Organs, Organ Systems, Organisms

Question 2

Human Cell Composition

Answer 2

Ions and Small Molecules (4%)
Phospholipids (2%)
DNA (1%)
RNA (6%)
Proteins (15%)
Polysaccharides (2%)

Question 3

Bonds to form Macromolecules

Bonds to form Macromolecular Assemblies

Answer 3

Covalent

Non-Covalent

Question 4

Element definition

Answer 4

can’t be chemically converted into other substances

Question 5

Acid

Answer 5

Proton (H+) donor, pH<7

Question 6

Base

Answer 6

Proton (H+) acceptor, pH>7

Question 7

Isomerism definition

Answer 7

same molecular formulae with different arrangement of functional groups and carbon atoms

Question 8

Stereoisomerism definition

Answer 8

involves different orientations in space of groups within a molecule, can be reflected and are deemed chiral. (AKA optical isomerism, enantiomers).

Question 9

RACEMIC

Answer 9

has equal amounts of left and right handed enantiomers so NO optical activity

Question 10

Homeostasis definition

Answer 10

maintenance of static.constant conditions in the internal environment

Question 11

Multicellular Organism meaning for cells and homeostasis

Answer 11

Cells become specialised and its the interaction/communication between cells that contributes to homeostasis

Question 12

Bathing medium of cells

Answer 12

Extracellular fluid (ECF), which dictates the external environment and is very stable

Question 13

ECF values for pH

Answer 13

Normal Value: 7.4
Normal Range: 7.3 - 7.5
Non-lethal Limits: 6.9 - 8.0
Below normal = acidosis
Above normal = alkalosis

Question 14

Control System for the body

Answer 14

Stimulus - Receptor - Afferent Pathway - Integrating Centre - Efferent Pathway - Effector - Response - Feedback
NO system is perfect and so exhibit a continuous cycle of fluctuations above and below the norm

Question 15

Control Concepts

Answer 15

Negative Feedback - most common
Positive Feedback - rare and non-homeostatic
Feed-Forward Control
Parametric = adaptive control
Predictive = anticipatory control

Question 16

Cellular Communication mechanisms

Answer 16

Direct:
Juxtacrine - physical contact between signalling and target
Gap Junctions - intercellular connection connects cytoplasms

via ECF:
Autocrine - cell signals to itself
Paracrine - signal molecule in ECF acts on nearby cells
Endocrine - hormones transported through bloodstream over long distances
Neuronal - target = nerve, muscle, gland over long distances
Neuroendocrine - combined neural and endocrine signalling where neutron secretes hormone into blood

Question 17

Examples of neural and hormonal control

Answer 17

Neural = baroreceptor reflex
Endocrine = Plasma Glucose

Question 18

Positive Feedback example

Answer 18

Cervical contractions from foetus pushing against cervix

Question 19

The membrane

Answer 19

self-arranging phospholipid bilayer

Phospholipid with hydrophilic head and hydrophobic tail

Question 20

The Nucleus

Answer 20

Largest Organelle
Generally cells only have one but can be multinucleate (skeletal muscle) or anuclear (RBC’s)
Stores the cells genetic info (DNA) and has nucleoli with protein/DNA/RNA masses

Question 21

The nuclear envelope

Answer 21

double membrane around nucleus perforated by nuclear pores formed by rings of proteins

Question 22

Ribosomes

Answer 22

make proteins - read messenger RNA and assemble amino acids through tRNA in a process called transcription
Found free in cytoplasm, on membranes (RER or nuc. env.) or in other organelles (nucleus or mitochondria)

Question 23

Endoplasmic Reticulum

Answer 23

system of channels (cisternae) enclosed by membrane

Can be rough or smooth

Question 24

Smooth ER

Answer 24

no ribosomes
synthesis of fats and lipids
synthesis steroid hormones
detoxification
Ca storage (sarcoplasmic reticulum in muscle)

Question 25

Rough ER

Answer 25

covered with ribosomes produces phospholipids and proteins of plasma membrane synthesises proteins