Bio + Chem + Physics Flashcards
1 key feature of nutrition
- taking in material for energy, development and growth
2 features of excretion
- removal of waste products of metabolism
+ toxic material
+ substances in excess - from organisms
1 key feature of reproduction
- the processes of reproducing more of the same kind of organisms.
2 features of growth
- permanent increase in size and dry mass
- by increase in cell number
+ increase in cell size
+ both
3 features of sensitivity
- detect or sense stimuli
- in the internal or external environment
- to make appropriate responses
3 features of respiration
- the chemical reaction in cells
- breaks down nutrient molecules
- release energy for metabolism
2 features of movement
- an action by an organism or a part of an organism
- causing a change of position or place
Factors of diffusion?
- Temperature
- Surface area
- Concentration gradient (Steepness)
- volume
- distance/thickness of the membrane
What state of matter does diffusion occur in?
- liquids and gases
Does diffusion use energy?
- Diffusion is a passive process
When does diffusion last?
- Until all molecules are evenly spread
What is diffusion?
- the net movement of molecules and ions
- from a region of higher concentration to lower concentration
- Down a concentration gradient
Animal cell vs. Plant cell, which will burst in pure water? Why?
animal will burst
Define plasmolysed cell
Cell shrinks until it’s shred, because it loses water (due to osmosis)
F
In a turgid cell, the outward pressure of the cytoplasm on a cell wall is called
Cell expands because it contains a lot of water (due to osmosis)
Turgid = Expands
What is a partially permeable membrane?
A membrane only allows some substances to go through it.
What is osmosis?
- Diffusion of water through a partially permeable membrane
- From a solution from high water concentration to low water concentration’s solution (higher water potential to lower water potential).
What thing don’t change by force
temperature (sometimes - air resistance)
density
mass
what force is needed to maintain a circular motion
The force directed toward the centre of the circle (centripetal force)
does constant speed require resultant force
NOOOOOOOOOOOOOOOOOOOOOOOOOOOOOO
Tips
look carefully at the arrow
equilibrium =
No resultant force = no acceleration = constant speed = no resultant moment
Does change in direction = a resultant force that exists
YESSSSSSSSSSSSSSSSSSSSSSS
for an object to be stable, the object must have
- wide base
- centre of mass is directly over its base or pivot
where is the centre of mass in a uniform object (e.g cube)
in the centre
2 gas types of gas pressure in a mercury barometer
atmospheric gas + trapped gas
how to calculate pressure underwater
Pressure = depth x density x gravitational strength
Density formula
Density = Mass/Volume ρ = m/V
Mass vs. Weight
Mass = amount of matter in an object (unit: kg) Weight = The force of gravity on an object (unit: N)
Speed vs. Velocity
Speed: A measure of how fast an object is moving, scalar quantity
Eg: 9 m/s
Velocity: A measure of how fast an object is moving (magnitude), including its direction, vector quantity
Eg: 9 m/s to the left
Scalar vs. Vector unit
Scalar unit: A unit measures the magnitude only (example: speed, mass, etc).
Vector: A unit measures both magnitude and direction (example: velocity, force, etc).
Relation between speed, time, and distance
distance = speed x time
Rearrange to find the others.
Acceleration is
A measure of the rate of change of velocity over time.
Change in direction is also acceleration too because velocity involves direction.
Formula to calculate force
Force = mass x acceleration
F = ma
Define the turning effect of a force
When applying a force on an object that “sticks” on a point, called a pivot, it will turn. We say that it has a turning effect.
That is, the force has a turning effect on that object.
We can also say that as the “moment of force”
Moment formula
Moment = Force x distance from pivot
unit: The units inputted
example:
Force: N; Distance = m => moment = Nm.
Factors that affect the turning effect of the force
- The force
- The distance from the pivot (more distance = more turning effect)
is photosynthesis a characteristic
NOOOOOOOOOOOOOOOOOOOOOOOOOOO, only plants could perform photosynthesis
What is the equation for magnification
size of the image
——————————- = x ……
size of the real object
What is the Rf value
distance moved by the solvent
What is turgor pressure?
• Water pressure inside cells pushing outwards
What is the name of lipid in the liquid state?
oil
What is the name of lipid in the solid state?
FAT
What atoms do lipid consist of
Carbon, hydrogen, oxygen
2 uses of lipid
- Provide the energy for the whole body
+ Reserved some fat by storing it under the skin, to produce energy for later - insulate the body
Why are we cooking oil mostly from the seeds of plants?
Because seeds usually stored fats for the germination state
What are the chemical reactions called inside every living organism?
metabolism
When will metabolic reactions take place?
Metabolic reactions take place only if the reacting chemicals are dissolved in water
Why is water important to living organisms(e.g)?
- Reactions need water, because the chemical dissolve in water, so if cells dry out and have no water, reactions stop and the cell died
Functions of water in the body
+ removal of waste substances in urine
+ Cooling mechanism
+ transport in blood
1 gram of carbohydrates equal to how much energy
17kJ of energy
What can you tell from the formula of glucose?
6 Carbon atoms; 12 Hydrogen atoms and 6 Oxygen atoms (C6H12O6).
In what form of carbohydrates do most organisms use for respiration
glucose
In what form do animals transport carbohydrates in their blood
Glucose
In what form do animals store their carbohydrates in cell
Glycogen
In what form of carbohydrates do plants use for transportation?
Sucrose
In what form of carbohydrates do plants use for storage?
Starch
Define & describe monosaccharides
- 1 simple sugar molecule
- simplest kind of carbohydrate
- Soluble in water, tastes sweet
Define & describe disaccharides
- 2 simple sugar molecules joined together
- Soluble in water, tastes sweet
Define & describe polysaccharides
- Many molecules of simple sugar team up
- Insoluble, do not taste sweet
Element vs. compound
Element: a substance that is made up of 1 type of atom
Compound: a substance that is made up of 2 or more types of atoms
What is the maximum number of electrons that shell 1 and 2 can hold
shell 1: 2
shell 2: 8
How to separate solid + solid
depends on its properties \+ density \+ magnetism \+ solubility \+ sublimation
how to separate solid + liquid
filtration + centrifugation
how to separate liquid + liquid (immiscible)
separating funnel or decanting (Pour off)
How to separate liquid + liquid; gas + gas
fractional distillation
How to separate MANY solid + liquid
chromatography
When to put the locating agents during the chromatography process
After chromatography
What is semi-metal
metalloids
Trends from metal to nonmetal
- less metallic
- more non-metallic
- more electronegativity
- more shells
- more stable (atom size decreasing)
Does transition metal coloured
yes
Metallic bonding?
- Held together by electrostatic force
- Metal are packed closely together
- atoms lose their electrons -> positive
- Free electrons are delocalised
Ionic bonding?
- Involve transferring electrons from one atom to another
- The oppositely charged ions are being held together by the electrostatic force
- conduct electricity when molten
=> Strong electrostatic force between oppositely charged ions in all directions -> more energy needed to separate
Covalent bond
bond is formed by the sharing of a pair of electrons between 2 atoms
Small covalent molecule
the very weak intermolecular force between molecules
Giant covalent structure
strong covalent bonds, extended in every direction
What is inertia
the tendency of an object to continue in its state of REST or in MOTION
What is the resultant force
- the third force
- If the forces acting on the object is unbalanced
- If you are using the vector diagram
- The sum of all forces acting an object
- Has the same effect as the reaction forces
What type of quantity is the force
Vector, increase in size and direction
What do you call an object being squashed
compression
What do you call an object being stretched
tension
How to calculate the pressure of the liquid
pressure = p x g x h
pascal (Pa) = density (kg/m3) x gravitaional force (kg m/s^2) x height (m)
What is an organic substance
SUBSTANCE must contain carbon atoms + hydrogen atoms
Which inorganic substances does a plant use to make carbohydrate
Water + carbon dioxide
What is chlorophyll
the green pigment, found in chloroplasts, that
absorbs energy from sunlight, used to drive
photosynthesis
What kind of cell makes the cuticle on a leaf
epidermal cells
The function of cuticle cells
Prevent water loss
What are stomata
small holes, usually in the bottom of a leaf, enables the gaseous exchange
What is guard cell
surrounding a stoma, which can change its shape and open or close the stoma
Do epidermal cells contain chloroplasts
No
What substances does a plant need to be able to convert glucose into proteins
Sulfur + nitrate
Why is glucose not very good for storage in a leaf
it’s highly reactive
