Key concepts in Biology

flashcards about key concepts in biology

What is the meaning of prokaryotic?

single celled organism that has no nucleus

What is eukaryotic?

organism that has a nucleus

Example of eukaryotic cells

animal

plant cells

example of prokaryotic cells

bacteria

organelles

structures in a cell that have different functions

nucleus

• contains DNA

Cytoplasm

• jelly like substance that chemical reactions occur in

Cell membrane

• controls what goes in and out of the cell

Mitochondria

• where aerobic respiration takes place in to provide energy for the cell

Ribosomes

• where protein synthesis occurs in

• Found on a structure called the rough endoplasmic reticulum

Chloroplasts

• where photosynthesis takes place providing food for the plant

• contain chlorophyll pigment which makes plants green

what does a permanent vacuole

• contain cell sap found in the cytoplasm

• - provides strength for cell

what does the cell wall do

• made from cellulose

• provide strength for the cell

what does a flagella

Long thin tails that make bacteria cells move

how do cells specialise

by undergoing differentiation

what is differentiation

the cells gains ne sub- cellular structures for it to be suited to it’s role

what are the sub- cellular structures does sperm have

• streamlined head and long tail

• a lot of mitochondria

• acrosome at the top of the head which has digestive enzymes to break down outer membrane of the egg cells

• haploid nucleus- half the amount (23 chromosome)

What sub-cellular structures does the egg cell have

• surrounded by a membrane that only allows one sperm during fertilisation

• a lot of mitochondria to provide energy source for the embryo

• large size and cytoplasm to allow quick division

What sub- cellular structures does a ciliated epithelial cell have

• long hair-like processes called CILIA to waft bacteria trapped by sticky mucus own to the stomach where it is killed by the stomach acid

What sub- cellular structures does the root hair cell have

• large surface area so more water can move in

• large permanent vacuole affect speed of movement to cell

• mitochondria to provide energy from respiration

What sub- cellular structures does a xylem cell have

• when it is formed, a chemical called lignin is deposited to cause the cells to die.

• they become hollow and a tube is formed

• lignin is deposited in spirals to help the cell withstand the pressure of water movement

What sub- cellular structures does the phloem cell have?

• cell walls form structures called sieve plates and break down to allow substances to move from cell to cell

• the energy is supplied by the mitochondria of the companion cells

What is this number 11 of a microscope?

stage

What is number 1?

Eyepiece

What is number 12?

coarse adjustment

what is number 8?

light source

What is number 2?

nose piece

What is number 4?

Objective lens

When was the electron microscope discovered?

1930s

What is the approximate magnification of an electron microscope?

2,000,000

How do you calculate magnification of a light microscope?

magnification of eyepiece X magnification

How do you calculate size of an object?

size of image/ magnification

What are enzymes?

biological catalysts that increase the rate of reaction without being used up

what happens when the active site and enzyme combine?

it make an enzyme- substrate complex

What does an enzyme need to work well?

optimum temperature and pH

What happens if the temperature is too hot?

The bonds that hold the enzyme break down

What happens to the active site if the temperature is too high?

active site changes shape

What does protease break down?

proteins

What does amylase break down starch into?

sugars

If protease breaks down proteins what do they break down into…?

amino acids

what does lipase break down lipids into?

fatty acids and glycerol

How do you calculate percentage change?

change in mass/start mass